Provided by: moosefs-chunkserver_4.57.5-1_amd64 
NAME
mfschunkserver.cfg - main configuration file for mfschunkserver
DESCRIPTION
The file mfschunkserver.cfg contains configuration of MooseFS chunkserver process.
SYNTAX
Syntax is:
OPTION = VALUE
Lines starting with # character are ignored as comments.
STARTUP OPTIONS
Changes in this section require process restart.
WORKING_USER
user to run daemon as
WORKING_GROUP
group to run daemon as; optional value - if empty then default user group will be used
SYSLOG_IDENT
name of process to place in syslog messages; default is mfschunkserver
LOCK_MEMORY
whether to perform mlockall() to avoid swapping out mfschunkserver process; default is 0, i.e. no
LIMIT_GLIBC_MALLOC_ARENAS
limit malloc arenas to given value - prevents server from using huge amount of virtual memory
(Linux only, default is 4)
DISABLE_OOM_KILLER
disable out of memory killer (Linux only, default is 1)
NICE_LEVEL
nice level to run daemon with; default is -19; note: process must be started as root to increase
priority, if setting of priority fails, process retains the nice level it started with
FILE_UMASK
set default umask for group and others (user has always 0); default is 027 - block write for group
and block all for others
DATA_PATH
where to store daemon lock file
ALLOW_STARTING_WITH_INVALID_DISKS
when set to one chunkserver will not abort start even when incorrect entries are found in
'mfshdd.cfg' file; default is 0 (do not start with invalid entries)
CAN_USE_MMAP
using mmap for allocation can slightly reduce ram usage and give a silight performance boost, but
on certain architectures/kernels can lead to problems - especially on architectures with more than
one physical CPU; default is 0
RUNTIME OPTIONS
Changes in this section require only process reload.
HDD_CONF_FILENAME
alternate location/name of mfshdd.cfg file
HDD_TEST_SPEED
Speed of background chunk tests in MB/s per disk (formally entry defined in mfshdd.cfg). Value can
be given as a decimal number; default is 1.0
HDD_MIN_TEST_INTERVAL
prevents from testing chunk integrity when last I/O (including test) was performed less than
HDD_MIN_TEST_INTERVAL ago; default is 1 day; for value formatting see TIME
HDD_FADVISE_MIN_TIME
If possible use posix_fadvise(POSIX_DONTNEED) after each chunk test (but only if last I/O
operation was performed more than HDD_FADVISE_MIN_TIME ago). Using zero will always perform
posix_fadvise (flush cache) and using negative value will never flush cache after tests. This
setting is valid only for systems that support posix_fadivise; default is 1 day; for value
formatting see TIME
HDD_LEAVE_SPACE_DEFAULT
how much space should be left unused on each hard drive; number format:
[0-9]*(.[0-9]*)?([kMGTPE]|[KMGTPE]i)?B? ; default is 256MiB; examples: 0.5GB, .5G, 2.56GiB, 1256M
etc.
HDD_REBALANCE_UTILIZATION
percent of total work time the chunkserver is allowed to spend on hdd space rebalancing; default
is 20
HDD_HIGH_SPEED_REBALANCE_LIMIT
maximum simultaneous writes per disk in high speed disk rebalance (0 means use standard rebalance;
default is 0)
HDD_ERROR_TOLERANCE_COUNT, HDD_ERROR_TOLERANCE_PERIOD
how many i/o errors (COUNT) to tolerate in given amount of seconds (PERIOD) on a single hard
drive; if the number of errors exceeds this setting, the offending hard drive will be marked as
damaged; defaults are 2 and 600
HDD_FSYNC_BEFORE_CLOSE
enables/disables fsync before chunk closing; default is 0 (off)
HDD_SPARSIFY_ON_WRITE
enables/disables sparsification (skip leading and trailing zeroz) during writing new block;
default is 1 (on)
HDD_RR_CHUNK_COUNT
how many chunks should be created in one directory before moving to the next one; higher values
are better with most OSes caching algorithms, low values lead to more even chunk distribution;
default is 10000 which works best in most cases
HDD_KEEP_DUPLICATES_HOURS
how many hours duplicate chunks should be kept before deleting (default is one week); changing
this value and reloading will reset the counter; for value formatting see TIME
WORKERS_MAX, WORKERS_MAX_IDLE
maximum number of active workers and maximum number of idle workers; defaults are 250 and 40
SYSLOG_MIN_LEVEL
minimum level of messages that will be reported by chunkserver; levels in order of importance:
ERROR, WARNING, NOTICE, INFO, DEBUG (default is INFO)
SYSLOG_ELEVATE_TO
reported messages of level lower than set by this option will be elevated to this level (i.e. if
SYSLOG_MIN_LEVEL is set to DEBUG and SYSLOG_ELEVATE_TO is set to NOTICE, all INFO and DEBUG
messages will be sent to syslog as NOTICE ; default is NOTICE)
MASTER CONNECTION OPTIONS
Changes in this section require only process reload.
LABELS labels string defined as a set of letters (case insensitive) separated by coma or semicolon;
default is empty - no labels
BIND_HOST
local address to use for master connections; default is *, i.e. default local address
MASTER_HOST
MooseFS master host, IP is allowed only in single-master installations; default is mfsmaster
MASTER_PORT
MooseFS master command port; default is 9420
MASTER_CONTROL_PORT
(pro only) MooseFS master control port; default is 9419
MASTER_TIMEOUT
timeout in seconds for master connections (if not 0); If this value is zero then chunkserver sets
it initially to 10 and asks master for this value. default is 0 (ask master).
MASTER_RECONNECTION_DELAY
delay in seconds before trying to reconnect to master after disconnection (default is 5)
AUTH_CODE
authentication string (used only when master requires authorization)
CHUNKS_PER_REGISTER_PACKET
maximum number of chunks system will try to put in a single register message (default is 1000,
limits 100-10000)
CLIENTS CONNECTION OPTIONS
Changes in this section require only process reload.
CSSERV_LISTEN_HOST
IP address to listen on for client (mount) connections (* means any)
CSSERV_LISTEN_PORT
port to listen on for client (mount) connections (default is 9422)
TIME
For config variables that define time without requiring a single, specific unit, time can be defined as a
number of seconds (integer) or a time period in one of two possible formats:
first format: #.#T where T is one of: s-seconds, m-minutes, h-hours, d-days or w-weeks; fractions of
seconds will be rounded to full seconds
second format: #w#d#h#m#s, any number of definitions can be ommited, but the remaining definitions must
be in order (so #d#m is still a valid definition, but #m#d is not); ranges: s,m: 0 to 59, h: 0 to 23, d:
0 t o 6, w is unlimited and the first definition is also always unlimited (i.e. for #d#h#m d will be
unlimited)
Notice! For variable HDD_KEEP_DUPLICATES_HOURS only h,d and w time units are accepted and a value without
a time unit is treated as hours; fractions are rounded to full hours.
Examples:
1.5h is the same as 1h30m, is the same as 90m, is the same as 5400s, is the same as 5400
2.5d is the same as 2d12h, is the same as 60h; 1d36h is not a valid time period (h is not the first
definition, so it is bound by range 0 to 23)
1.03m is the same as 62s (61.8 seconds will be rounded up to 62)
COPYRIGHT
Copyright (C) 2025 Jakub Kruszona-Zawadzki, Saglabs SA
This file is part of MooseFS.
MooseFS is free software; you can redistribute it and/or modify it under the terms of the GNU General
Public License as published by the Free Software Foundation, version 2 (only).
MooseFS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
License for more details.
You should have received a copy of the GNU General Public License along with MooseFS; if not, write to
the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02111-1301, USA or visit
http://www.gnu.org/licenses/gpl-2.0.html
SEE ALSO
mfschunkserver(8), mfshdd.cfg(5)
MooseFS 4.57.5-1 February 2025 mfschunkserver.cfg(5)