Provided by: duplicity_0.8.21-1build1_amd64 
NAME
duplicity - Encrypted incremental backup to local or remote storage.
SYNOPSIS
For detailed descriptions for each command see chapter ACTIONS.
duplicity [full|incremental] [options] source_directory target_url
duplicity verify [options] [--compare-data] [--file-to-restore <relpath>] [--time time] source_url
target_directory
duplicity collection-status [options] [--file-changed <relpath>] target_url
duplicity list-current-files [options] [--time time] target_url
duplicity [restore] [options] [--file-to-restore <relpath>] [--time time] source_url target_directory
duplicity remove-older-than <time> [options] [--force] target_url
duplicity remove-all-but-n-full <count> [options] [--force] target_url
duplicity remove-all-inc-of-but-n-full <count> [options] [--force] target_url
duplicity cleanup [options] [--force] target_url
duplicity replicate [options] [--time time] source_url target_url
DESCRIPTION
Duplicity incrementally backs up files and folders into tar-format volumes encrypted with GnuPG and
places them to a remote (or local) storage backend. See chapter URL FORMAT for a list of all supported
backends and how to address them. Because duplicity uses librsync, incremental backups are space
efficient and only record the parts of files that have changed since the last backup. Currently
duplicity supports deleted files, full Unix permissions, uid/gid, directories, symbolic links, fifos,
etc., but not hard links.
If you are backing up the root directory /, remember to --exclude /proc, or else duplicity will probably
crash on the weird stuff in there.
EXAMPLES
Here is an example of a backup, using sftp to back up /home/me to some_dir on the other.host machine:
duplicity /home/me sftp://uid@other.host/some_dir
If the above is run repeatedly, the first will be a full backup, and subsequent ones will be incremental.
To force a full backup, use the full action:
duplicity full /home/me sftp://uid@other.host/some_dir
or enforcing a full every other time via --full-if-older-than <time> , e.g. a full every month:
duplicity --full-if-older-than 1M /home/me sftp://uid@other.host/some_dir
Now suppose we accidentally delete /home/me and want to restore it the way it was at the time of last
backup:
duplicity sftp://uid@other.host/some_dir /home/me
Duplicity enters restore mode because the URL comes before the local directory. If we wanted to restore
just the file "Mail/article" in /home/me as it was three days ago into /home/me/restored_file:
duplicity -t 3D --file-to-restore Mail/article sftp://uid@other.host/some_dir
/home/me/restored_file
The following command compares the latest backup with the current files:
duplicity verify sftp://uid@other.host/some_dir /home/me
Finally, duplicity recognizes several include/exclude options. For instance, the following will backup
the root directory, but exclude /mnt, /tmp, and /proc:
duplicity --exclude /mnt --exclude /tmp --exclude /proc / file:///usr/local/backup
Note that in this case the destination is the local directory /usr/local/backup. The following will
backup only the /home and /etc directories under root:
duplicity --include /home --include /etc --exclude '**' / file:///usr/local/backup
Duplicity can also access a repository via ftp. If a user name is given, the environment variable
FTP_PASSWORD is read to determine the password:
FTP_PASSWORD=mypassword duplicity /local/dir ftp://user@other.host/some_dir
ACTIONS
Duplicity knows action commands, which can be finetuned with options.
The actions for backup (full,incr) and restoration (restore) can as well be left out as duplicity detects
in what mode it should switch to by the order of target URL and local folder. If the target URL comes
before the local folder a restore is in order, is the local folder before target URL then this folder is
about to be backed up to the target URL.
If a backup is in order and old signatures can be found duplicity automatically performs an incremental
backup.
Note: The following explanations explain some but not all options that can be used in connection with
that action command. Consult the OPTIONS section for more detailed informations.
full <folder> <url>
Perform a full backup. A new backup chain is started even if signatures are available for an
incremental backup.
incr <folder> <url>
If this is requested an incremental backup will be performed. Duplicity will abort if no old
signatures can be found.
verify [--compare-data] [--time <time>] [--file-to-restore <rel_path>] <url> <local_path>
Verify tests the integrity of the backup archives at the remote location by downloading each file
and checking both that it can restore the archive and that the restored file matches the signature
of that file stored in the backup, i.e. compares the archived file with its hash value from
archival time. Verify does not actually restore and will not overwrite any local files. Duplicity
will exit with a non-zero error level if any files do not match the signature stored in the
archive for that file. On verbosity level 4 or higher, it will log a message for each file that
differs from the stored signature. Files must be downloaded to the local machine in order to
compare them. Verify does not compare the backed-up version of the file to the current local copy
of the files unless the --compare-data option is used (see below).
The --file-to-restore option restricts verify to that file or folder. The --time option allows to
select a backup to verify. The --compare-data option enables data comparison (see below).
collection-status [--file-changed <relpath>]<url>
Summarize the status of the backup repository by printing the chains and sets found, and the
number of volumes in each.
list-current-files [--time <time>] <url>
Lists the files contained in the most current backup or backup at time. The information will be
extracted from the signature files, not the archive data itself. Thus the whole archive does not
have to be downloaded, but on the other hand if the archive has been deleted or corrupted, this
command will not detect it.
restore [--file-to-restore <relpath>] [--time <time>] <url> <target_folder>
You can restore the full monty or selected folders/files from a specific time. Use the relative
path as it is printed by list-current-files. Usually not needed as duplicity enters restore mode
when it detects that the URL comes before the local folder.
remove-older-than <time> [--force] <url>
Delete all backup sets older than the given time. Old backup sets will not be deleted if backup
sets newer than time depend on them. See the TIME FORMATS section for more information. Note,
this action cannot be combined with backup or other actions, such as cleanup. Note also that
--force will be needed to delete the files instead of just listing them.
remove-all-but-n-full <count> [--force] <url>
Delete all backups sets that are older than the count:th last full backup (in other words, keep
the last count full backups and associated incremental sets). count must be larger than zero. A
value of 1 means that only the single most recent backup chain will be kept. Note that --force
will be needed to delete the files instead of just listing them.
remove-all-inc-of-but-n-full <count> [--force] <url>
Delete incremental sets of all backups sets that are older than the count:th last full backup (in
other words, keep only old full backups and not their increments). count must be larger than
zero. A value of 1 means that only the single most recent backup chain will be kept intact. Note
that --force will be needed to delete the files instead of just listing them.
cleanup [--force] <url>
Delete the extraneous duplicity files on the given backend. Non-duplicity files, or files in
complete data sets will not be deleted. This should only be necessary after a duplicity session
fails or is aborted prematurely. Note that --force will be needed to delete the files instead of
just listing them.
replicate [--time time] <source_url> <target_url>
Replicate backup sets from source to target backend. Files will be (re)-encrypted and
(re)-compressed depending on normal backend options. Signatures and volumes will not get
recomputed, thus options like --volsize or --max-blocksize have no effect. When --time time is
given, only backup sets older than time will be replicated.
OPTIONS
--allow-source-mismatch
Do not abort on attempts to use the same archive dir or remote backend to back up different
directories. duplicity will tell you if you need this switch.
--archive-dir path
The archive directory. NOTE: This option changed in 0.6.0. The archive directory is now
necessary in order to manage persistence for current and future enhancements. As such, this
option is now used only to change the location of the archive directory. The archive directory
should not be deleted, or duplicity will have to recreate it from the remote repository (which may
require decrypting the backup contents).
When backing up or restoring, this option specifies that the local archive directory is to be
created in path. If the archive directory is not specified, the default will be to create the
archive directory in ~/.cache/duplicity/.
The archive directory can be shared between backups to multiple targets, because a subdirectory of
the archive dir is used for individual backups (see --name ).
The combination of archive directory and backup name must be unique in order to separate the data
of different backups.
The interaction between the --archive-dir and the --name options allows for four possible
combinations for the location of the archive dir:
1. neither specified (default)
~/.cache/duplicity/hash-of-url
2. --archive-dir=/arch, no --name
/arch/hash-of-url
3. no --archive-dir, --name=foo
~/.cache/duplicity/foo
4. --archive-dir=/arch, --name=foo
/arch/foo
--asynchronous-upload
(EXPERIMENTAL) Perform file uploads asynchronously in the background, with respect to volume
creation. This means that duplicity can upload a volume while, at the same time, preparing the
next volume for upload. The intended end-result is a faster backup, because the local CPU and your
bandwidth can be more consistently utilized. Use of this option implies additional need for disk
space in the temporary storage location; rather than needing to store only one volume at a time,
enough storage space is required to store two volumes.
--backend-retry-delay number
Specifies the number of seconds that duplicity waits after an error has occured before attempting
to repeat the operation.
--cf-backend backend
Allows the explicit selection of a cloudfiles backend. Defaults to pyrax. Alternatively you might
choose cloudfiles.
--b2-hide-files
Causes Duplicity to hide files in B2 instead of deleting them. Useful in combination with B2's
lifecycle rules.
--compare-data
Enable data comparison of regular files on action verify. This conducts a verify as described
above to verify the integrity of the backup archives, but additionally compares restored files to
those in target_directory. Duplicity will not replace any files in target_directory. Duplicity
will exit with a non-zero error level if the files do not correctly verify or if any files from
the archive differ from those in target_directory. On verbosity level 4 or higher, it will log a
message for each file that differs from its equivalent in target_directory.
--copy-links
Resolve symlinks during backup. Enabling this will resolve & back up the symlink's file/folder
data instead of the symlink itself, potentially increasing the size of the backup.
--dry-run
Calculate what would be done, but do not perform any backend actions
--encrypt-key key-id
When backing up, encrypt to the given public key, instead of using symmetric (traditional)
encryption. Can be specified multiple times. The key-id can be given in any of the formats
supported by GnuPG; see gpg(1), section "HOW TO SPECIFY A USER ID" for details.
--encrypt-secret-keyring filename
This option can only be used with --encrypt-key, and changes the path to the secret keyring for
the encrypt key to filename This keyring is not used when creating a backup. If not specified, the
default secret keyring is used which is usually located at .gnupg/secring.gpg
--encrypt-sign-key key-id
Convenience parameter. Same as --encrypt-key key-id --sign-key key-id.
--exclude shell_pattern
Exclude the file or files matched by shell_pattern. If a directory is matched, then files under
that directory will also be matched. See the FILE SELECTION section for more information.
--exclude-device-files
Exclude all device files. This can be useful for security/permissions reasons or if duplicity is
not handling device files correctly.
--exclude-filelist filename
Excludes the files listed in filename, with each line of the filelist interpreted according to the
same rules as --include and --exclude. See the FILE SELECTION section for more information.
--exclude-if-present filename
Exclude directories if filename is present. Allows the user to specify folders that they do not
wish to backup by adding a specified file (e.g. ".nobackup") instead of maintaining a
comprehensive exclude/include list.
--exclude-older-than time
Exclude any files whose modification date is earlier than the specified time. This can be used to
produce a partial backup that contains only recently changed files. See the TIME FORMATS section
for more information.
--exclude-other-filesystems
Exclude files on file systems (identified by device number) other than the file system the root of
the source directory is on.
--exclude-regexp regexp
Exclude files matching the given regexp. Unlike the --exclude option, this option does not match
files in a directory it matches. See the FILE SELECTION section for more information.
--file-prefix, --file-prefix-manifest, --file-prefix-archive, --file-prefix-signature
Adds a prefix to all files, manifest files, archive files, and/or signature files.
The same set of prefixes must be passed in on backup and restore.
If both global and type-specific prefixes are set, global prefix will go before type-specific
prefixes.
See also A NOTE ON FILENAME PREFIXES
--file-to-restore path
This option may be given in restore mode, causing only path to be restored instead of the entire
contents of the backup archive. path should be given relative to the root of the directory backed
up.
--full-if-older-than time
Perform a full backup if an incremental backup is requested, but the latest full backup in the
collection is older than the given time. See the TIME FORMATS section for more information.
--force
Proceed even if data loss might result. Duplicity will let the user know when this option is
required.
--ftp-passive
Use passive (PASV) data connections. The default is to use passive, but to fallback to regular if
the passive connection fails or times out.
--ftp-regular
Use regular (PORT) data connections.
--gio Use the GIO backend and interpret any URLs as GIO would.
--hidden-encrypt-key key-id
Same as --encrypt-key, but it hides user's key id from encrypted file. It uses the gpg's --hidden-
recipient command to obfuscate the owner of the backup. On restore, gpg will automatically try all
available secret keys in order to decrypt the backup. See gpg(1) for more details.
--ignore-errors
Try to ignore certain errors if they happen. This option is only intended to allow the restoration
of a backup in the face of certain problems that would otherwise cause the backup to fail. It is
not ever recommended to use this option unless you have a situation where you are trying to
restore from backup and it is failing because of an issue which you want duplicity to ignore. Even
then, depending on the issue, this option may not have an effect.
Please note that while ignored errors will be logged, there will be no summary at the end of the
operation to tell you what was ignored, if anything. If this is used for emergency restoration of
data, it is recommended that you run the backup in such a way that you can revisit the backup log
(look for lines containing the string IGNORED_ERROR).
If you ever have to use this option for reasons that are not understood or understood but not your
own responsibility, please contact duplicity maintainers. The need to use this option under
production circumstances would normally be considered a bug.
--imap-full-address email_address
The full email address of the user name when logging into an imap server. If not supplied just
the user name part of the email address is used.
--imap-mailbox option
Allows you to specify a different mailbox. The default is "INBOX". Other languages may require a
different mailbox than the default.
--gpg-binary file_path
Allows you to force duplicity to use file_path as gpg command line binary. Can be an absolute or
relative file path or a file name. Default value is 'gpg'. The binary will be localized via the
PATH environment variable.
--gpg-options options
Allows you to pass options to gpg encryption. The options list should be of the form "--opt1
--opt2=parm" where the string is quoted and the only spaces allowed are between options.
--include shell_pattern
Similar to --exclude but include matched files instead. Unlike --exclude, this option will also
match parent directories of matched files (although not necessarily their contents). See the FILE
SELECTION section for more information.
--include-filelist filename
Like --exclude-filelist, but include the listed files instead. See the FILE SELECTION section for
more information.
--include-regexp regexp
Include files matching the regular expression regexp. Only files explicitly matched by regexp
will be included by this option. See the FILE SELECTION section for more information.
--log-fd number
Write specially-formatted versions of output messages to the specified file descriptor. The
format used is designed to be easily consumable by other programs.
--log-file filename
Write specially-formatted versions of output messages to the specified file. The format used is
designed to be easily consumable by other programs.
--max-blocksize number
determines the number of the blocks examined for changes during the diff process. For files < 1MB
the blocksize is a constant of 512. For files over 1MB the size is given by:
file_blocksize = int((file_len / (2000 * 512)) * 512)
return min(file_blocksize, config.max_blocksize)
where config.max_blocksize defaults to 2048. If you specify a larger max_blocksize, your difftar
files will be larger, but your sigtar files will be smaller. If you specify a smaller
max_blocksize, the reverse occurs. The --max-blocksize option should be in multiples of 512.
--name symbolicname
Set the symbolic name of the backup being operated on. The intent is to use a separate name for
each logically distinct backup. For example, someone may use "home_daily_s3" for the daily backup
of a home directory to Amazon S3. The structure of the name is up to the user, it is only
important that the names be distinct. The symbolic name is currently only used to affect the
expansion of --archive-dir , but may be used for additional features in the future. Users running
more than one distinct backup are encouraged to use this option.
If not specified, the default value is a hash of the backend URL.
--no-compression
Do not use GZip to compress files on remote system.
--no-encryption
Do not use GnuPG to encrypt files on remote system.
--no-print-statistics
By default duplicity will print statistics about the current session after a successful backup.
This switch disables that behavior.
--null-separator
Use nulls (\0) instead of newlines (\n) as line separators, which may help when dealing with
filenames containing newlines. This affects the expected format of the files specified by the
--{include|exclude}-filelist switches as well as the format of the directory statistics file.
--numeric-owner
On restore always use the numeric uid/gid from the archive and not the archived user/group names,
which is the default behaviour. Recommended for restoring from live cds which might have the
users with identical names but different uids/gids.
--do-not-restore-ownership
Ignores the uid/gid from the archive and keeps the current user's one. Recommended for restoring
data to mounted filesystem which do not support Unix ownership or when root privileges are not
available.
--num-retries number
Number of retries to make on errors before giving up.
--old-filenames
Use the old filename format (incompatible with Windows/Samba) rather than the new filename format.
--par2-options options
Verbatim options to pass to par2.
--par2-redundancy percent
Adjust the level of redundancy in percent for Par2 recovery files (default 10%).
--progress
When selected, duplicity will output the current upload progress and estimated upload time. To
annotate changes, it will perform a first dry-run before a full or incremental, and then runs the
real operation estimating the real upload progress.
--progress-rate number
Sets the update rate at which duplicity will output the upload progress messages (requires
--progress option). Default is to print the status each 3 seconds.
--rename <original path> <new path>
Treats the path orig in the backup as if it were the path new. Can be passed multiple times. An
example:
duplicity restore --rename Documents/metal Music/metal sftp://uid@other.host/some_dir /home/me
--rsync-options options
Allows you to pass options to the rsync backend. The options list should be of the form
"opt1=parm1 opt2=parm2" where the option string is quoted and the only spaces allowed are between
options. The option string will be passed verbatim to rsync, after any internally generated option
designating the remote port to use. Here is a possibly useful example:
duplicity --rsync-options="--partial-dir=.rsync-partial" /home/me rsync://uid@other.host/some_dir
--s3-european-buckets
When using the Amazon S3 backend, create buckets in Europe instead of the default (requires
--s3-use-new-style ). Also see the EUROPEAN S3 BUCKETS section.
This option does not apply when using the newer boto3 backend, which does not create buckets.
See also A NOTE ON AMAZON S3 below.
--s3-unencrypted-connection
Don't use SSL for connections to S3.
This may be much faster, at some cost to confidentiality.
With this option, anyone who can observe traffic between your computer and S3 will be able to
tell: that you are using Duplicity, the name of the bucket, your AWS Access Key ID, the increment
dates and the amount of data in each increment.
This option affects only the connection, not the GPG encryption of the backup increment files.
Unless that is disabled, an observer will not be able to see the file names or contents.
This option is not available when using the newer boto3 backend.
See also A NOTE ON AMAZON S3 below.
--s3-use-new-style
When operating on Amazon S3 buckets, use new-style subdomain bucket addressing. This is now the
preferred method to access Amazon S3, but is not backwards compatible if your bucket name contains
upper-case characters or other characters that are not valid in a hostname.
This option has no effect when using the newer boto3 backend, which will always use new style
subdomain bucket naming.
See also A NOTE ON AMAZON S3 below.
--s3-use-rrs
Store volumes using Reduced Redundancy Storage when uploading to Amazon S3. This will lower the
cost of storage but also lower the durability of stored volumes to 99.99% instead the
99.999999999% durability offered by Standard Storage on S3.
--s3-use-ia
Store volumes using Standard - Infrequent Access when uploading to Amazon S3. This storage class
has a lower storage cost but a higher per-request cost, and the storage cost is calculated against
a 30-day storage minimum. According to Amazon, this storage is ideal for long-term file storage,
backups, and disaster recovery.
--s3-use-onezone-ia
Store volumes using One Zone - Infrequent Access when uploading to Amazon S3. This storage is
similar to Standard - Infrequent Access, but only stores object data in one Availability Zone.
--s3-use-glacier
Store volumes using Glacier S3 when uploading to Amazon S3. This storage class has a lower cost of
storage but a higher per-request cost along with delays of up to 12 hours from the time of
retrieval request. This storage cost is calculated against a 90-day storage minimum. According to
Amazon this storage is ideal for data archiving and long-term backup offering 99.999999999%
durability. To restore a backup you will have to manually migrate all data stored on AWS Glacier
back to Standard S3 and wait for AWS to complete the migration. Notice: Duplicity will store the
manifest.gpg files from full and incremental backups on AWS S3 standard storage to allow quick
retrieval for later incremental backups, all other data is stored in S3 Glacier.
--s3-use-deep-archive
Store volumes using Glacier Deep Archive S3 when uploading to Amazon S3. This storage class has a
lower cost of storage but a higher per-request cost along with delays of up to 48 hours from the
time of retrieval request. This storage cost is calculated against a 180-day storage minimum.
According to Amazon this storage is ideal for data archiving and long-term backup offering
99.999999999% durability. To restore a backup you will have to manually migrate all data stored
on AWS Glacier Deep Archive back to Standard S3 and wait for AWS to complete the migration.
Notice: Duplicity will store the manifest.gpg files from full and incremental backups on AWS S3
standard storage to allow quick retrieval for later incremental backups, all other data is stored
in S3 Glacier Deep Archive.
Glacier Deep Archive is only available when using the newer boto3 backend.
--s3-use-multiprocessing
Allow multipart volumne uploads to S3 through multiprocessing. This option requires Python 2.6 and
can be used to make uploads to S3 more efficient. If enabled, files duplicity uploads to S3 will
be split into chunks and uploaded in parallel. Useful if you want to saturate your bandwidth or if
large files are failing during upload.
This has no effect when using the newer boto3 backend. Boto3 always attempts to multiprocessing
when it is believed it will be more efficient.
See also A NOTE ON AMAZON S3 below.
--s3-use-server-side-encryption
Allow use of server side encryption in S3
--s3-multipart-chunk-size
Chunk size (in MB) used for S3 multipart uploads. Make this smaller than --volsize to maximize the
use of your bandwidth. For example, a chunk size of 10MB with a volsize of 30MB will result in 3
chunks per volume upload.
See also A NOTE ON AMAZON S3 below.
--s3-multipart-max-procs
Specify the maximum number of processes to spawn when performing a multipart upload to S3. By
default, this will choose the number of processors detected on your system (e.g. 4 for a 4-core
system). You can adjust this number as required to ensure you don't overload your system while
maximizing the use of your bandwidth.
This has no effect when using the newer boto3 backend.
See also A NOTE ON AMAZON S3 below.
--s3-multipart-max-timeout
You can control the maximum time (in seconds) a multipart upload can spend on uploading a single
chunk to S3. This may be useful if you find your system hanging on multipart uploads or if you'd
like to control the time variance when uploading to S3 to ensure you kill connections to slow S3
endpoints.
This has no effect when using the newer boto3 backend.
See also A NOTE ON AMAZON S3 below.
--s3-region-name
Specifies the region of the S3 storage.
This is currently only used in the newer boto3 backend.
--s3-endpoint-url
Specifies the endpoint URL of the S3 storage.
This is currently only used in the newer boto3 backend.
--azure-blob-tier
Standard storage tier used for backup files (Hot|Cool|Archive).
--azure-max-single-put-size
Specify the number of the largest supported upload size where the Azure library makes only one put
call. If the content size is known and below this value the Azure library will only perform one
put request to upload one block. The number is expected to be in bytes.
--azure-max-block-size
Specify the number for the block size used by the Azure library to upload blobs if it is split
into multiple blocks. The maximum block size the service supports is 104857600 (100MiB) and the
default is 4194304 (4MiB)
--azure-max-connections
Specify the number of maximum connections to transfer one blob to Azure blob size exceeds 64MB.
The default values is 2.
--scp-command command
(only ssh pexpect backend with --use-scp enabled) The command will be used instead of "scp" to
send or receive files. To list and delete existing files, the sftp command is used.
See also A NOTE ON SSH BACKENDS section SSH pexpect backend.
--sftp-command command
(only ssh pexpect backend) The command will be used instead of "sftp".
See also A NOTE ON SSH BACKENDS section SSH pexpect backend.
--short-filenames
If this option is specified, the names of the files duplicity writes will be shorter (about 30
chars) but less understandable. This may be useful when backing up to MacOS or another OS or FS
that doesn't support long filenames.
--sign-key key-id
This option can be used when backing up, restoring or verifying. When backing up, all backup
files will be signed with keyid key. When restoring, duplicity will signal an error if any remote
file is not signed with the given key-id. The key-id can be given in any of the formats supported
by GnuPG; see gpg(1), section "HOW TO SPECIFY A USER ID" for details. Should be specified only
once because currently only one signing key is supported. Last entry overrides all other entries.
See also A NOTE ON SYMMETRIC ENCRYPTION AND SIGNING
--ssh-askpass
Tells the ssh backend to prompt the user for the remote system password, if it was not defined in
target url and no FTP_PASSWORD env var is set. This password is also used for passphrase-
protected ssh keys.
--ssh-options options
Allows you to pass options to the ssh backend. Can be specified multiple times or as a space
separated options list. The options list should be of the form "-oOpt1='parm1' -oOpt2='parm2'"
where the option string is quoted and the only spaces allowed are between options. The option
string will be passed verbatim to both scp and sftp, whose command line syntax differs slightly
hence the options should therefore be given in the long option format described in ssh_config(5).
example of a list:
duplicity --ssh-options="-oProtocol=2 -oIdentityFile='/my/backup/id'" /home/me
scp://user@host/some_dir
example with multiple parameters:
duplicity --ssh-options="-oProtocol=2" --ssh-options="-oIdentityFile='/my/backup/id'" /home/me
scp://user@host/some_dir
NOTE: The ssh paramiko backend currently supports only the -i or -oIdentityFile or
-oUserKnownHostsFile or -oGlobalKnownHostsFile settings. If needed provide more host specific
options via ssh_config file.
--ssl-cacert-file file
(only webdav & lftp backend) Provide a cacert file for ssl certificate verification.
See also A NOTE ON SSL CERTIFICATE VERIFICATION.
--ssl-cacert-path path/to/certs/
(only webdav backend and python 2.7.9+ OR lftp+webdavs and a recent lftp) Provide a path to a
folder containing cacert files for ssl certificate verification.
See also A NOTE ON SSL CERTIFICATE VERIFICATION.
--ssl-no-check-certificate
(only webdav & lftp backend) Disable ssl certificate verification.
See also A NOTE ON SSL CERTIFICATE VERIFICATION.
--swift-storage-policy
Use this storage policy when operating on Swift containers.
See also A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS.
--metadata-sync-mode mode
This option defaults to 'partial', but you can set it to 'full'
Use 'partial' to avoid syncing metadata for backup chains that you are not going to use. This
saves time when restoring for the first time, and lets you restore an old backup that was
encrypted with a different passphrase by supplying only the target passphrase.
Use 'full' to sync metadata for all backup chains on the remote.
--tempdir directory
Use this existing directory for duplicity temporary files instead of the system default, which is
usually the /tmp directory. This option supersedes any environment variable.
See also ENVIRONMENT VARIABLES.
-ttime, --time time, --restore-time time
Specify the time from which to restore or list files.
--time-separator char
Use char as the time separator in filenames instead of colon (":").
--timeout seconds
Use seconds as the socket timeout value if duplicity begins to timeout during network operations.
The default is 30 seconds.
--use-agent
If this option is specified, then --use-agent is passed to the GnuPG encryption process and it
will try to connect to gpg-agent before it asks for a passphrase for --encrypt-key or --sign-key
if needed.
Note: Contrary to previous versions of duplicity, this option will also be honored by GnuPG 2 and
newer versions. If GnuPG 2 is in use, duplicity passes the option --pinentry-mode=loopback to the
the gpg process unless --use-agent is specified on the duplicity command line. This has the effect
that GnuPG 2 uses the agent only if --use-agent is given, just like GnuPG 1.
--verbosity level, -vlevel
Specify output verbosity level (log level). Named levels and corresponding values are 0 Error, 2
Warning, 4 Notice (default), 8 Info, 9 Debug (noisiest).
level may also be
a character: e, w, n, i, d
a word: error, warning, notice, info, debug
The options -v4, -vn and -vnotice are functionally equivalent, as are the mixed/upper-case
versions -vN, -vNotice and -vNOTICE.
--version
Print duplicity's version and quit.
--volsize number
Change the volume size to number MB. Default is 200MB.
ENVIRONMENT VARIABLES
TMPDIR, TEMP, TMP
In decreasing order of importance, specifies the directory to use for temporary files (inherited
from Python's tempfile module). Eventually the option --tempdir supercedes any of these.
FTP_PASSWORD
Supported by most backends which are password capable. More secure than setting it in the backend
url (which might be readable in the operating systems process listing to other users on the same
machine).
PASSPHRASE
This passphrase is passed to GnuPG. If this is not set, the user will be prompted for the
passphrase.
SIGN_PASSPHRASE
The passphrase to be used for --sign-key. If ommitted and sign key is also one of the keys to
encrypt against PASSPHRASE will be reused instead. Otherwise, if passphrase is needed but not set
the user will be prompted for it.
Other environment variables may be used to configure specific backends. See the notes for the
particular backend.
URL FORMAT
Duplicity uses the URL format (as standard as possible) to define data locations. The generic format for
a URL is:
scheme://[user[:password]@]host[:port]/[/]path
It is not recommended to expose the password on the command line since it could be revealed to anyone
with permissions to do process listings, it is permitted however. Consider setting the environment
variable FTP_PASSWORD instead, which is used by most, if not all backends, regardless of it's name.
In protocols that support it, the path may be preceded by a single slash, '/path', to represent a
relative path to the target home directory, or preceded by a double slash, '//path', to represent an
absolute filesystem path.
Note:
Scheme (protocol) access may be provided by more than one backend. In case the default backend is
buggy or simply not working in a specific case it might be worth trying an alternative
implementation. Alternative backends can be selected by prefixing the scheme with the name of the
alternative backend e.g. ncftp+ftp:// and are mentioned below the scheme's syntax summary.
Formats of each of the URL schemes follow:
Amazon Drive Backend
ad://some_dir
See also A NOTE ON AMAZON DRIVE
Azure
azure://container-name
See also A NOTE ON AZURE ACCESS
B2
b2://account_id[:application_key]@bucket_name/[folder/]
Box
box:///some_dir[?config=path_to_config]
See also A NOTE ON BOX ACCESS
Cloud Files (Rackspace)
cf+http://container_name
See also A NOTE ON CLOUD FILES ACCESS
Dropbox
dpbx:///some_dir
Make sure to read A NOTE ON DROPBOX ACCESS first!
Local file path
file://[relative|/absolute]/local/path
FISH (Files transferred over Shell protocol) over ssh
fish://user[:pwd]@other.host[:port]/[relative|/absolute]_path
FTP
ftp[s]://user[:password]@other.host[:port]/some_dir
NOTE: use lftp+, ncftp+ prefixes to enforce a specific backend, default is lftp+ftp://...
Google Docs
gdocs://user[:password]@other.host/some_dir
NOTE: use pydrive+, gdata+ prefixes to enforce a specific backend, default is pydrive+gdocs://...
Google Cloud Storage
gs://bucket[/prefix]
HSI
hsi://user[:password]@other.host/some_dir
hubiC
cf+hubic://container_name
See also A NOTE ON HUBIC
IMAP email storage
imap[s]://user[:password]@host.com[/from_address_prefix]
See also A NOTE ON IMAP
MEGA.nz cloud storage (only works for accounts created prior to November 2018, uses "megatools")
mega://user[:password]@mega.nz/some_dir
NOTE: if not given in the URL, relies on password being stored within $HOME/.megarc (as used by
the "megatools" utilities)
MEGA.nz cloud storage (works for all MEGA accounts, uses "MEGAcmd" tools)
megav2://user[:password]@mega.nz/some_dir megav3://user[:password]@mega.nz/some_dir[?no_logout=1]
(For latest MEGAcmd)
NOTE: despite "MEGAcmd" no longer uses a configuration file, for convenience storing the user
password this backend searches it in the $HOME/.megav2rc file (same syntax as the old
$HOME/.megarc)
[Login]
Username = MEGA_USERNAME
Password = MEGA_PASSWORD
OneDrive Backend
onedrive://some_dir
Par2 Wrapper Backend
par2+scheme://[user[:password]@]host[:port]/[/]path
See also A NOTE ON PAR2 WRAPPER BACKEND
Rclone Backend
rclone://remote:/some_dir
See also A NOTE ON RCLONE BACKEND
Rsync via daemon
rsync://user[:password]@host.com[:port]::[/]module/some_dir
Rsync over ssh (only key auth)
rsync://user@host.com[:port]/[relative|/absolute]_path
S3 storage (Amazon)
s3://host[:port]/bucket_name[/prefix]
s3+http://bucket_name[/prefix]
defaults to the legacy boto backend based on boto v2 (last update 2018/07)
alternatively try the newer boto3+s3://bucket_name[/prefix]
For details see A NOTE ON AMAZON S3 and see also A NOTE ON EUROPEAN S3 BUCKETS below.
SCP/SFTP access
scp://.. or
sftp://user[:pwd]@other.host[:port]/[relative|/absolute]_path
defaults are paramiko+scp:// and paramiko+sftp://
alternatively try pexpect+scp://, pexpect+sftp://, lftp+sftp://
See also --ssh-askpass, --ssh-options and A NOTE ON SSH BACKENDS.
Swift (Openstack)
swift://container_name[/prefix]
See also A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS
Public Cloud Archive (OVH)
pca://container_name[/prefix]
See also A NOTE ON PCA ACCESS
Tahoe-LAFS
tahoe://alias/directory
WebDAV
webdav[s]://user[:password]@other.host[:port]/some_dir
alternatively try lftp+webdav[s]://
pydrive
pydrive://<service account' email address>@developer.gserviceaccount.com/some_dir
See also A NOTE ON PYDRIVE BACKEND below.
gdrive
gdrive://<service account' email address>@developer.gserviceaccount.com/some_dir
See also A NOTE ON GDRIVE BACKEND below.
multi
multi:///path/to/config.json
See also A NOTE ON MULTI BACKEND below.
MediaFire
mf://user[:password]@mediafire.com/some_dir
See also A NOTE ON MEDIAFIRE BACKEND below.
TIME FORMATS
duplicity uses time strings in two places. Firstly, many of the files duplicity creates will have the
time in their filenames in the w3 datetime format as described in a w3 note at http://www.w3.org/TR/NOTE-
datetime. Basically they look like "2001-07-15T04:09:38-07:00", which means what it looks like. The
"-07:00" section means the time zone is 7 hours behind UTC.
Secondly, the -t, --time, and --restore-time options take a time string, which can be given in any of
several formats:
1. the string "now" (refers to the current time)
2. a sequences of digits, like "123456890" (indicating the time in seconds after the epoch)
3. A string like "2002-01-25T07:00:00+02:00" in datetime format
4. An interval, which is a number followed by one of the characters s, m, h, D, W, M, or Y
(indicating seconds, minutes, hours, days, weeks, months, or years respectively), or a series of
such pairs. In this case the string refers to the time that preceded the current time by the
length of the interval. For instance, "1h78m" indicates the time that was one hour and 78 minutes
ago. The calendar here is unsophisticated: a month is always 30 days, a year is always 365 days,
and a day is always 86400 seconds.
5. A date format of the form YYYY/MM/DD, YYYY-MM-DD, MM/DD/YYYY, or MM-DD-YYYY, which indicates
midnight on the day in question, relative to the current time zone settings. For instance,
"2002/3/5", "03-05-2002", and "2002-3-05" all mean March 5th, 2002.
FILE SELECTION
When duplicity is run, it searches through the given source directory and backs up all the files
specified by the file selection system. The file selection system comprises a number of file selection
conditions, which are set using one of the following command line options:
--exclude
--exclude-device-files
--exclude-if-present
--exclude-filelist
--exclude-regexp
--include
--include-filelist
--include-regexp
Each file selection condition either matches or doesn't match a given file. A given file is excluded by
the file selection system exactly when the first matching file selection condition specifies that the
file be excluded; otherwise the file is included.
For instance,
duplicity --include /usr --exclude /usr /usr scp://user@host/backup
is exactly the same as
duplicity /usr scp://user@host/backup
because the include and exclude directives match exactly the same files, and the --include comes first,
giving it precedence. Similarly,
duplicity --include /usr/local/bin --exclude /usr/local /usr scp://user@host/backup
would backup the /usr/local/bin directory (and its contents), but not /usr/local/doc.
The include, exclude, include-filelist, and exclude-filelist options accept some extended shell globbing
patterns. These patterns can contain *, **, ?, and [...] (character ranges). As in a normal shell, *
can be expanded to any string of characters not containing "/", ? expands to any character except "/",
and [...] expands to a single character of those characters specified (ranges are acceptable). The new
special pattern, **, expands to any string of characters whether or not it contains "/". Furthermore, if
the pattern starts with "ignorecase:" (case insensitive), then this prefix will be removed and any
character in the string can be replaced with an upper- or lowercase version of itself.
Remember that you may need to quote these characters when typing them into a shell, so the shell does not
interpret the globbing patterns before duplicity sees them.
The --exclude pattern option matches a file if:
1. pattern can be expanded into the file's filename, or
2. the file is inside a directory matched by the option.
Conversely, the --include pattern matches a file if:
1. pattern can be expanded into the file's filename, or
2. the file is inside a directory matched by the option, or
3. the file is a directory which contains a file matched by the option.
For example,
--exclude /usr/local
matches e.g. /usr/local, /usr/local/lib, and /usr/local/lib/netscape. It is the same as --exclude
/usr/local --exclude '/usr/local/**'.
On the other hand
--include /usr/local
specifies that /usr, /usr/local, /usr/local/lib, and /usr/local/lib/netscape (but not /usr/doc) all be
backed up. Thus you don't have to worry about including parent directories to make sure that included
subdirectories have somewhere to go.
Finally,
--include ignorecase:'/usr/[a-z0-9]foo/*/**.py'
would match a file like /usR/5fOO/hello/there/world.py. If it did match anything, it would also match
/usr. If there is no existing file that the given pattern can be expanded into, the option will not
match /usr alone.
The --include-filelist, and --exclude-filelist, options also introduce file selection conditions. They
direct duplicity to read in a text file (either ASCII or UTF-8), each line of which is a file
specification, and to include or exclude the matching files. Lines are separated by newlines or nulls,
depending on whether the --null-separator switch was given. Each line in the filelist will be
interpreted as a globbing pattern the way --include and --exclude options are interpreted, except that
lines starting with "+ " are interpreted as include directives, even if found in a filelist referenced by
--exclude-filelist. Similarly, lines starting with "- " exclude files even if they are found within an
include filelist.
For example, if file "list.txt" contains the lines:
/usr/local
- /usr/local/doc
/usr/local/bin
+ /var
- /var
then --include-filelist list.txt would include /usr, /usr/local, and /usr/local/bin. It would exclude
/usr/local/doc, /usr/local/doc/python, etc. It would also include /usr/local/man, as this is included
within /user/local. Finally, it is undefined what happens with /var. A single file list should not
contain conflicting file specifications.
Each line in the filelist will also be interpreted as a globbing pattern the way --include and --exclude
options are interpreted. For instance, if the file "list.txt" contains the lines:
dir/foo
+ dir/bar
- **
Then --include-filelist list.txt would be exactly the same as specifying --include dir/foo --include
dir/bar --exclude ** on the command line.
Finally, the --include-regexp and --exclude-regexp options allow files to be included and excluded if
their filenames match a python regular expression. Regular expression syntax is too complicated to
explain here, but is covered in Python's library reference. Unlike the --include and --exclude options,
the regular expression options don't match files containing or contained in matched files. So for
instance
--include '[0-9]{7}(?!foo)'
matches any files whose full pathnames contain 7 consecutive digits which aren't followed by 'foo'.
However, it wouldn't match /home even if /home/ben/1234567 existed.
A NOTE ON AMAZON DRIVE
1. The API Keys used for Amazon Drive have not been granted production limits. Amazon do not say
what the development limits are and are not replying to to requests to whitelist duplicity. A
related tool, acd_cli, was demoted to development limits, but continues to work fine except for
cases of excessive usage. If you experience throttling and similar issues with Amazon Drive using
this backend, please report them to the mailing list.
2. If you previously used the acd+acdcli backend, it is strongly recommended to update to the ad
backend instead, since it interfaces directly with Amazon Drive. You will need to setup the OAuth
once again, but can otherwise keep your backups and config.
A NOTE ON AMAZON S3
When backing up to Amazon S3, two backend implementations are available. The schemes "s3" and "s3+http"
are implemented using the older boto library, which has been deprecated and is no longer supported. The
"boto3+s3" scheme is based on the newer boto3 library. This new backend fixes several known limitations
in the older backend, which have crept in as Amazon S3 has evolved while the deprecated boto library has
not kept up.
The boto3 backend should behave largely the same as the older S3 backend, but there are some differences
in the handling of some of the "S3" options. Additionally, there are some compatibility differences with
the new backed. Because of these reasons, both backends have been retained for the time being. See the
documentation for specific options regarding differences related to each backend.
The boto3 backend does not support bucket creation. This is a deliberate choice which simplifies the
code, and side steps problems related to region selection. Additionally, it is probably not a good
practice to give your backup role bucket creation rights. In most cases the role used for backups should
probably be limited to specific buckets.
The boto3 backend only supports newer domain style buckets. Amazon is moving to deprecate the older
bucket style, so migration is recommended. Use the older s3 backend for compatibility with backups
stored in buckets using older naming conventions.
The boto3 backend does not currently support initiating restores from the glacier storage class. When
restoring a backup from glacier or glacier deep archive, the backup files must first be restored out of
band. There are multiple options when restoring backups from cold storage, which vary in both cost and
speed. See Amazon's documentation for details.
A NOTE ON AZURE ACCESS
The Azure backend requires the Microsoft Azure Storage Blobs client library for Python to be installed on
the system. See REQUIREMENTS.
It uses the environment variable AZURE_CONNECTION_STRING (required). This string contains all necessary
information such as Storage Account name and the key for authentication. You can find it under Access
Keys for the storage account.
Duplicity will take care to create the container when performing the backup. Do not create it manually
before.
A container name (as given as the backup url) must be a valid DNS name, conforming to the following
naming rules:
1. Container names must start with a letter or number, and can contain only letters, numbers,
and the dash (-) character.
2. Every dash (-) character must be immediately preceded and followed by a letter or number;
consecutive dashes are not permitted in container names.
3. All letters in a container name must be lowercase.
4. Container names must be from 3 through 63 characters long.
These rules come from Azure; see https://docs.microsoft.com/en-us/rest/api/storageservices/naming-and-
referencing-containers--blobs--and-metadata
A NOTE ON BOX ACCESS
The box backend requires boxsdk with jwt support to be installed on the system. See REQUIREMENTS.
It uses the environment variable BOX_CONFIG_PATH (optional). This string contains the path to box custom
app's config.json. Either this environment variable or the config query parameter in the url need to be
specified, if both are specified, query paramter takes precedence.
Create a Box custom app
In order to use box backend, user need to create a box custom app in the box developer console
(https://app.box.com/developers/console).
After create a new custom app, please make sure it is configured as follow:
1. Choose "App Access Only" for "App Access Level"
2. Check "Write all files and folders stored in Box"
3. Generate a Public/Private Keypair
The user also need to grant the created custom app permission in the admin console
(https://app.box.com/master/custom-apps) by clicking the "+" button and enter the client_id which can be
found on the custom app's configuration page.
A NOTE ON CLOUD FILES ACCESS
Pyrax is Rackspace's next-generation Cloud management API, including Cloud Files access. The cfpyrax
backend requires the pyrax library to be installed on the system. See REQUIREMENTS.
Cloudfiles is Rackspace's now deprecated implementation of OpenStack Object Storage protocol. Users
wishing to use Duplicity with Rackspace Cloud Files should migrate to the new Pyrax plugin to ensure
support.
The backend requires python-cloudfiles to be installed on the system. See REQUIREMENTS.
It uses three environment variables for authentification: CLOUDFILES_USERNAME (required),
CLOUDFILES_APIKEY (required), CLOUDFILES_AUTHURL (optional)
If CLOUDFILES_AUTHURL is unspecified it will default to the value provided by python-cloudfiles, which
points to rackspace, hence this value must be set in order to use other cloud files providers.
A NOTE ON DROPBOX ACCESS
1. First of all Dropbox backend requires valid authentication token. It should be passed via
DPBX_ACCESS_TOKEN environment variable.
To obtain it please create 'Dropbox API' application at:
https://www.dropbox.com/developers/apps/create
Then visit app settings and just use 'Generated access token' under OAuth2 section.
Alternatively you can let duplicity generate access token itself. In such case temporary export
DPBX_APP_KEY , DPBX_APP_SECRET using values from app settings page and run duplicity
interactively.
It will print the URL that you need to open in the browser to obtain OAuth2 token for the
application. Just follow on-screen instructions and then put generated token to DPBX_ACCESS_TOKEN
variable. Once done, feel free to unset DPBX_APP_KEY and DPBX_APP_SECRET
2. "some_dir" must already exist in the Dropbox folder. Depending on access token kind it may be:
Full Dropbox: path is absolute and starts from 'Dropbox' root folder.
App Folder: path is related to application folder. Dropbox client will show it in
~/Dropbox/Apps/<app-name>
3. When using Dropbox for storage, be aware that all files, including the ones in the Apps folder,
will be synced to all connected computers. You may prefer to use a separate Dropbox account
specially for the backups, and not connect any computers to that account. Alternatively you can
configure selective sync on all computers to avoid syncing of backup files
A NOTE ON EUROPEAN S3 BUCKETS
Amazon S3 provides the ability to choose the location of a bucket upon its creation. The purpose is to
enable the user to choose a location which is better located network topologically relative to the user,
because it may allow for faster data transfers.
duplicity will create a new bucket the first time a bucket access is attempted. At this point, the bucket
will be created in Europe if --s3-european-buckets was given. For reasons having to do with how the
Amazon S3 service works, this also requires the use of the --s3-use-new-style option. This option turns
on subdomain based bucket addressing in S3. The details are beyond the scope of this man page, but it is
important to know that your bucket must not contain upper case letters or any other characters that are
not valid parts of a hostname. Consequently, for reasons of backwards compatibility, use of subdomain
based bucket addressing is not enabled by default.
Note that you will need to use --s3-use-new-style for all operations on European buckets; not just upon
initial creation.
You only need to use --s3-european-buckets upon initial creation, but you may may use it at all times for
consistency.
Further note that when creating a new European bucket, it can take a while before the bucket is fully
accessible. At the time of this writing it is unclear to what extent this is an expected feature of
Amazon S3, but in practice you may experience timeouts, socket errors or HTTP errors when trying to
upload files to your newly created bucket. Give it a few minutes and the bucket should function normally.
A NOTE ON FILENAME PREFIXES
Filename prefixes can be used in multi backend with mirror mode to define affinity rules. They can also
be used in conjunction with S3 lifecycle rules to transition archive files to Glacier, while keeping
metadata (signature and manifest files) on S3.
Duplicity does not require access to archive files except when restoring from backup.
A NOTE ON GOOGLE CLOUD STORAGE
Support for Google Cloud Storage relies on its Interoperable Access, which must be enabled for your
account. Once enabled, you can generate Interoperable Storage Access Keys and pass them to duplicity via
the GS_ACCESS_KEY_ID and GS_SECRET_ACCESS_KEY environment variables. Alternatively, you can run gsutil
config -a to have the Google Cloud Storage utility populate the ~/.boto configuration file.
Enable Interoperable Access: https://code.google.com/apis/console#:storage
Create Access Keys: https://code.google.com/apis/console#:storage:legacy
A NOTE ON HUBIC
The hubic backend requires the pyrax library to be installed on the system. See REQUIREMENTS. You will
need to set your credentials for hubiC in a file called ~/.hubic_credentials, following this pattern:
[hubic]
email = your_email
password = your_password
client_id = api_client_id
client_secret = api_secret_key
redirect_uri = http://localhost/
A NOTE ON IMAP
An IMAP account can be used as a target for the upload. The userid may be specified and the password
will be requested.
The from_address_prefix may be specified (and probably should be). The text will be used as the "From"
address in the IMAP server. Then on a restore (or list) command the from_address_prefix will distinguish
between different backups.
A NOTE ON MULTI BACKEND
The multi backend allows duplicity to combine the storage available in more than one backend store (e.g.,
you can store across a google drive account and a onedrive account to get effectively the combined
storage available in both). The URL path specifies a JSON formated config file containing a list of the
backends it will use. The URL may also specify "query" parameters to configure overall behavior. Each
element of the list must have a "url" element, and may also contain an optional "description" and an
optional "env" list of environment variables used to configure that backend.
Query Parameters
Query parameters come after the file URL in standard HTTP format for example:
multi:///path/to/config.json?mode=mirror&onfail=abort
multi:///path/to/config.json?mode=stripe&onfail=continue
multi:///path/to/config.json?onfail=abort&mode=stripe
multi:///path/to/config.json?onfail=abort
Order does not matter, however unrecognized parameters are considered an error.
mode=stripe
This mode (the default) performs round-robin access to the list of backends. In this mode, all
backends must be reliable as a loss of one means a loss of one of the archive files.
mode=mirror
This mode accesses backends as a RAID1-store, storing every file in every backend and reading
files from the first-successful backend. A loss of any backend should result in no failure. Note
that backends added later will only get new files and may require a manual sync with one of the
other operating ones.
onfail=continue
This setting (the default) continues all write operations in as best-effort. Any failure results
in the next backend tried. Failure is reported only when all backends fail a given operation with
the error result from the last failure.
onfail=abort
This setting considers any backend write failure as a terminating condition and reports the error.
Data reading and listing operations are independent of this and will try with the next backend on
failure.
JSON File Example
[
{
"description": "a comment about the backend"
"url": "abackend://myuser@domain.com/backup",
"env": [
{
"name" : "MYENV",
"value" : "xyz"
},
{
"name" : "FOO",
"value" : "bar"
}
],
"prefixes": ["prefix1_", "prefix2_"]
},
{
"url": "file:///path/to/dir"
}
]
A NOTE ON PAR2 WRAPPER BACKEND
Par2 Wrapper Backend can be used in combination with all other backends to create recovery files. Just
add par2+ before a regular scheme (e.g. par2+ftp://user@host/dir or par2+s3+http://bucket_name ). This
will create par2 recovery files for each archive and upload them all to the wrapped backend.
Before restoring, archives will be verified. Corrupt archives will be repaired on the fly if there are
enough recovery blocks available.
Use --par2-redundancy percent to adjust the size (and redundancy) of recovery files in percent.
A NOTE ON PYDRIVE BACKEND
The pydrive backend requires Python PyDrive package to be installed on the system. See REQUIREMENTS.
There are two ways to use PyDrive: with a regular account or with a "service account". With a service
account, a separate account is created, that is only accessible with Google APIs and not a web login.
With a regular account, you can store backups in your normal Google Drive.
To use a service account, go to the Google developers console at https://console.developers.google.com.
Create a project, and make sure Drive API is enabled for the project. Under "APIs and auth", click Create
New Client ID, then select Service Account with P12 key.
Download the .p12 key file of the account and convert it to the .pem format:
openssl pkcs12 -in XXX.p12 -nodes -nocerts > pydriveprivatekey.pem
The content of .pem file should be passed to GOOGLE_DRIVE_ACCOUNT_KEY environment variable for
authentification.
The email address of the account will be used as part of URL. See URL FORMAT above.
The alternative is to use a regular account. To do this, start as above, but when creating a new Client
ID, select "Installed application" of type "Other". Create a file with the following content, and pass
its filename in the GOOGLE_DRIVE_SETTINGS environment variable:
client_config_backend: settings
client_config:
client_id: <Client ID from developers' console>
client_secret: <Client secret from developers' console>
save_credentials: True
save_credentials_backend: file
save_credentials_file: <filename to cache credentials>
get_refresh_token: True
In this scenario, the username and host parts of the URL play no role; only the path matters. During the
first run, you will be prompted to visit an URL in your browser to grant access to your drive. Once
granted, you will receive a verification code to paste back into Duplicity. The credentials are then
cached in the file references above for future use.
A NOTE ON GDRIVE BACKEND
GDrive: is a rewritten PyDrive: backend with less dependencies, and a simpler setup - it uses the JSON
keys downloaded directly from Google Cloud Console.
Note Google has 2 drive methods, `Shared(previously Team) Drives` and `My Drive`, both can be shared but
require different addressing
For a Google Shared Drives folder
Share Drive ID specified as a query parameter, driveID, in the backend URL. Example:
gdrive://developer.gserviceaccount.com/target-folder/?driveID=<SHARED DRIVE ID>
For a Google My Drive based shared folder
MyDrive folder ID specified as a query parameter, myDriveFolderID, in the backend URL Example
export GOOGLE_SERVICE_ACCOUNT_URL=<serviceaccount-name>@<serviceaccount-
name>.iam.gserviceaccount.com
gdrive://${GOOGLE_SERVICE_ACCOUNT_URL}/<target-folder-name-in-
myDriveFolder>?myDriveFolderID=<google-myDrive-folder-id>
There are also two ways to authenticate to use GDrive: with a regular account or with a "service
account". With a service account, a separate account is created, that is only accessible with Google APIs
and not a web login. With a regular account, you can store backups in your normal Google Drive.
To use a service account, go to the Google developers console at https://console.developers.google.com.
Create a project, and make sure Drive API is enabled for the project. In the "Credentials" section, click
"Create credentials", then select Service Account with JSON key.
The GOOGLE_SERVICE_JSON_FILE environment variable needs to contain the path to the JSON file on duplicity
invocation.
export GOOGLE_SERVICE_JSON_FILE=<path-to-serviceaccount-credentials.json>
The alternative is to use a regular account. To do this, start as above, but when creating a new Client
ID, select "Create OAuth client ID", with application type of "Desktop app". Download the
client_secret.json file for the new client, and set the GOOGLE_CLIENT_SECRET_JSON_FILE environment
variable to the path to this file, and GOOGLE_CREDENTIALS_FILE to a path to a file where duplicity will
keep the authentication token - this location must be writable.
During the first run, you will be prompted to visit an URL in your browser to grant access to your drive.
Once granted, you will receive a verification code to paste back into Duplicity. The credentials are then
cached in the file references above for future use.
As a sanity check, GDrive checks the host and username from the URL against the JSON key, and refuses to
proceed if the addresses do not match. Either the email (for the service accounts) or Client ID (for
regular OAuth accounts) must be present in the URL. See URL FORMAT above.
A NOTE ON RCLONE BACKEND
Rclone is a powerful command line program to sync files and directories to and from various cloud storage
providers.
Once you have configured an rclone remote via
rclone config
and successfully set up a remote (e.g. gdrive for Google Drive), assuming you can list your remote files
with
rclone ls gdrive:mydocuments
you can start your backup with
duplicity /mydocuments rclone://gdrive:/mydocuments
Please note the slash after the second colon. Some storage provider will work with or without slash after
colon, but some other will not. Since duplicity will complain about malformed URL if a slash is not
present, always put it after the colon, and the backend will handle it for you.
A NOTE ON SSH BACKENDS
The ssh backends support sftp and scp/ssh transport protocols. This is a known user-confusing issue as
these are fundamentally different. If you plan to access your backend via one of those please inform
yourself about the requirements for a server to support sftp or scp/ssh access. To make it even more
confusing the user can choose between several ssh backends via a scheme prefix: paramiko+ (default),
pexpect+, lftp+... .
paramiko & pexpect support --use-scp, --ssh-askpass and --ssh-options. Only the pexpect backend allows
to define --scp-command and --sftp-command.
SSH paramiko backend (default) is a complete reimplementation of ssh protocols natively in python.
Advantages are speed and maintainability. Minor disadvantage is that extra packages are needed as listed
in REQUIREMENTS. In sftp (default) mode all operations are done via the according sftp commands. In scp
mode ( --use-scp ) though scp access is used for put/get operations but listing is done via ssh remote
shell.
SSH pexpect backend is the legacy ssh backend using the command line ssh binaries via pexpect. Older
versions used scp for get and put operations and sftp for list and delete operations. The current
version uses sftp for all four supported operations, unless the --use-scp option is used to revert to old
behavior.
SSH lftp backend is simply there because lftp can interact with the ssh cmd line binaries. It is meant
as a last resort in case the above options fail for some reason.
Why use sftp instead of scp? The change to sftp was made in order to allow the remote system to chroot
the backup, thus providing better security and because it does not suffer from shell quoting issues like
scp. Scp also does not support any kind of file listing, so sftp or ssh access will always be needed in
addition for this backend mode to work properly. Sftp does not have these limitations but needs an sftp
service running on the backend server, which is sometimes not an option.
A NOTE ON SSL CERTIFICATE VERIFICATION
Certificate verification as implemented right now [02.2016] only in the webdav and lftp backends. older
pythons 2.7.8- and older lftp binaries need a file based database of certification authority certificates
(cacert file).
Newer python 2.7.9+ and recent lftp versions however support the system default certificates (usually in
/etc/ssl/certs) and also giving an alternative ca cert folder via --ssl-cacert-path.
The cacert file has to be a PEM formatted text file as currently provided by the CURL project. See
http://curl.haxx.se/docs/caextract.html
After creating/retrieving a valid cacert file you should copy it to either
~/.duplicity/cacert.pem
~/duplicity_cacert.pem
/etc/duplicity/cacert.pem
Duplicity searches it there in the same order and will fail if it can't find it. You can however specify
the option --ssl-cacert-file <file> to point duplicity to a copy in a different location.
Finally there is the --ssl-no-check-certificate option to disable certificate verification alltogether,
in case some ssl library is missing or verification is not wanted. Use it with care, as even with self
signed servers manually providing the private ca certificate is definitely the safer option.
A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS
Swift is the OpenStack Object Storage service.
The backend requires python-switclient to be installed on the system. python-keystoneclient is also
needed to use OpenStack's Keystone Identity service. See REQUIREMENTS.
It uses following environment variables for authentification: SWIFT_USERNAME (required), SWIFT_PASSWORD
(required), SWIFT_AUTHURL (required), SWIFT_USERID (required, only for IBM Bluemix ObjectStorage),
SWIFT_TENANTID (required, only for IBM Bluemix ObjectStorage), SWIFT_REGIONNAME (required, only for IBM
Bluemix ObjectStorage), SWIFT_TENANTNAME (optional, the tenant can be included in the username)
If the user was previously authenticated, the following environment variables can be used instead:
SWIFT_PREAUTHURL (required), SWIFT_PREAUTHTOKEN (required)
If SWIFT_AUTHVERSION is unspecified, it will default to version 1.
A NOTE ON PCA ACCESS
PCA is a long-term data archival solution by OVH. It runs a slightly modified version of Openstack Swift
introducing latency in the data retrieval process. It is a good pick for a multi backend configuration
where receiving volumes while an other backend is used to store manifests and signatures.
The backend requires python-switclient to be installed on the system. python-keystoneclient is also
needed to interact with OpenStack's Keystone Identity service. See REQUIREMENTS.
It uses following environment variables for authentification: PCA_USERNAME (required), PCA_PASSWORD
(required), PCA_AUTHURL (required), PCA_USERID (optional), PCA_TENANTID (optional, but either the tenant
name or tenant id must be supplied) PCA_REGIONNAME (optional), PCA_TENANTNAME (optional, but either the
tenant name or tenant id must be supplied)
If the user was previously authenticated, the following environment variables can be used instead:
PCA_PREAUTHURL (required), PCA_PREAUTHTOKEN (required)
If PCA_AUTHVERSION is unspecified, it will default to version 2.
A NOTE ON MEDIAFIRE BACKEND
This backend requires mediafire python library to be installed on the system. See REQUIREMENTS.
Use URL escaping for username (and password, if provided via command line):
mf://duplicity%40example.com@mediafire.com/some_folder
The destination folder will be created for you if it does not exist.
A NOTE ON SYMMETRIC ENCRYPTION AND SIGNING
Signing and symmetrically encrypt at the same time with the gpg binary on the command line, as used
within duplicity, is a specifically challenging issue. Tests showed that the following combinations
proved working.
1. Setup gpg-agent properly. Use the option --use-agent and enter both passphrases (symmetric and sign
key) in the gpg-agent's dialog.
2. Use a PASSPHRASE for symmetric encryption of your choice but the signing key has an empty passphrase.
3. The used PASSPHRASE for symmetric encryption and the passphrase of the signing key are identical.
KNOWN ISSUES / BUGS
Hard links currently unsupported (they will be treated as non-linked regular files).
Bad signatures will be treated as empty instead of logging appropriate error message.
OPERATION AND DATA FORMATS
This section describes duplicity's basic operation and the format of its data files. It should not be
necessary to read this section to use duplicity.
The files used by duplicity to store backup data are tarfiles in GNU tar format. They can be produced
independently by rdiffdir(1). For incremental backups, new files are saved normally in the tarfile. But
when a file changes, instead of storing a complete copy of the file, only a diff is stored, as generated
by rdiff(1). If a file is deleted, a 0 length file is stored in the tar. It is possible to restore a
duplicity archive "manually" by using tar and then cp, rdiff, and rm as necessary. These duplicity
archives have the extension difftar.
Both full and incremental backup sets have the same format. In effect, a full backup set is an
incremental one generated from an empty signature (see below). The files in full backup sets will start
with duplicity-full while the incremental sets start with duplicity-inc. When restoring, duplicity
applies patches in order, so deleting, for instance, a full backup set may make related incremental
backup sets unusable.
In order to determine which files have been deleted, and to calculate diffs for changed files, duplicity
needs to process information about previous sessions. It stores this information in the form of tarfiles
where each entry's data contains the signature (as produced by rdiff) of the file instead of the file's
contents. These signature sets have the extension sigtar.
Signature files are not required to restore a backup set, but without an up-to-date signature, duplicity
cannot append an incremental backup to an existing archive.
To save bandwidth, duplicity generates full signature sets and incremental signature sets. A full
signature set is generated for each full backup, and an incremental one for each incremental backup.
These start with duplicity-full-signatures and duplicity-new-signatures respectively. These signatures
will be stored both locally and remotely. The remote signatures will be encrypted if encryption is
enabled. The local signatures will not be encrypted and stored in the archive dir (see --archive-dir ).
REQUIREMENTS
Duplicity requires a POSIX-like operating system with a python interpreter version 2.6+ installed. It is
best used under GNU/Linux.
Some backends also require additional components (probably available as packages for your specific
platform):
Amazon Drive backend
python-requests - http://python-requests.org
python-requests-oauthlib - https://github.com/requests/requests-oauthlib
azure backend (Azure Storage Blob Service)
Microsoft Azure Storage Blobs client library for Python - https://pypi.org/project/azure-storage-
blob/
boto backend (S3 Amazon Web Services, Google Cloud Storage)
boto version 2.0+ - http://github.com/boto/boto
box backend (box.com)
boxsdk - https://github.com/box/box-python-sdk
cfpyrax backend (Rackspace Cloud) and hubic backend (hubic.com)
Rackspace CloudFiles Pyrax API - http://docs.rackspace.com/sdks/guide/content/python.html
dpbx backend (Dropbox)
Dropbox Python SDK - https://www.dropbox.com/developers/reference/sdk
gdocs gdata backend (legacy Google Docs backend)
Google Data APIs Python Client Library - http://code.google.com/p/gdata-python-client/
gdocs pydrive backend(default)
see pydrive backend
gio backend (Gnome VFS API)
PyGObject - http://live.gnome.org/PyGObject
D-Bus (dbus)- http://www.freedesktop.org/wiki/Software/dbus
lftp backend (needed for ftp, ftps, fish [over ssh] - also supports sftp, webdav[s])
LFTP Client - http://lftp.yar.ru/
MEGA backend (only works for accounts created prior to November 2018) (mega.nz)
megatools client - https://github.com/megous/megatools
MEGA v2 and v3 backend (works for all MEGA accounts) (mega.nz)
MEGAcmd client - https://mega.nz/cmd
multi backend
Multi -- store to more than one backend
(also see A NOTE ON MULTI BACKEND ) below.
ncftp backend (ftp, select via ncftp+ftp://)
NcFTP - http://www.ncftp.com/
OneDrive backend (Microsoft OneDrive)
python-requests-oauthlib - https://github.com/requests/requests-oauthlib
Par2 Wrapper Backend
par2cmdline - http://parchive.sourceforge.net/
pydrive backend
PyDrive -- a wrapper library of google-api-python-client - https://pypi.python.org/pypi/PyDrive
(also see A NOTE ON PYDRIVE BACKEND ) below.
rclone backend
rclone - https://rclone.org/
rsync backend
rsync client binary - http://rsync.samba.org/
ssh paramiko backend (default)
paramiko (SSH2 for python) - http://pypi.python.org/pypi/paramiko (downloads);
http://github.com/paramiko/paramiko (project page)
pycrypto (Python Cryptography Toolkit) - http://www.dlitz.net/software/pycrypto/
ssh pexpect backend
sftp/scp client binaries OpenSSH - http://www.openssh.com/
Python pexpect module - http://pexpect.sourceforge.net/pexpect.html
swift backend (OpenStack Object Storage)
Python swiftclient module - https://github.com/openstack/python-swiftclient/
Python keystoneclient module - https://github.com/openstack/python-keystoneclient/
webdav backend
certificate authority database file for ssl certificate verification of HTTPS connections -
http://curl.haxx.se/docs/caextract.html
(also see A NOTE ON SSL CERTIFICATE VERIFICATION).
Python kerberos module for kerberos authentication - https://github.com/02strich/pykerberos
MediaFire backend
MediaFire Python Open SDK - https://pypi.python.org/pypi/mediafire/
AUTHOR
Original Author - Ben Escoto <bescoto@stanford.edu>
Current Maintainer - Kenneth Loafman <kenneth@loafman.com>
Continuous Contributors
Edgar Soldin, Mike Terry
Most backends were contributed individually. Information about their authorship may be found in the
according file's header.
Also we'd like to thank everybody posting issues to the mailing list or on launchpad, sending in patches
or contributing otherwise. Duplicity wouldn't be as stable and useful if it weren't for you.
A special thanks goes to rsync.net, a Cloud Storage provider with explicit support for duplicity, for
several monetary donations and for providing a special "duplicity friends" rate for their offsite backup
service. Email info@rsync.net for details.
SEE ALSO
rdiffdir(1), python(1), rdiff(1), rdiff-backup(1).
Version 0.8.21 November 09, 2021 DUPLICITY(1)