NAME

       mfschunkserver.cfg - main configuration file for *mfschunkserver*

DESCRIPTION

       The file mfschunkserver.cfg contains configuration of LizardFS chunkserver process.

SYNTAX

       Syntax is:

       OPTION = VALUE
           Lines starting with # character are ignored.

OPTIONS

       Configuration options:

       DATA_PATH
           where to store files with usage statistics and daemon lock file

       LABEL
           the label of this chunkserver (for tiering)

       WORKING_USER
           user to run daemon as

       WORKING_GROUP
           group to run daemon as (optional - 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)

       NICE_LEVEL
           nice level to run daemon with (default is -19 if possible; note: process must be
           started as root to increase priority)

       MASTER_HOST
           address of LizardFS master host to connect with (default is mfsmaster)

       MASTER_PORT
           number of LizardFS master port to connect with (default is 9420)

       MASTER_RECONNECTION_DELAY
           delay in seconds before trying to reconnect to the master server after disconnection
           (default is 5)

       MASTER_TIMEOUT
           timeout (in seconds) for the master server connection (default is 60, minimum is 0.01)

       BIND_HOST
           local address to use for connecting with the master server (default is *, i.e. default
           local address)

       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)

       CSSERV_TIMEOUT
           timeout (in seconds) for client (mount) connections (default is 5)

       HDD_CONF_FILENAME
           alternative name of mfshdd.cfg file

       HDD_LEAVE_SPACE_DEFAULT
           free space threshold to set volume as 100% utilized when there is less than given
           amount of free space left (default is "4GiB"). This number is always added to the used
           disk space reported by chunkserver.

       HDD_TEST_FREQ
           chunk test period in seconds (default is 10)

       HDD_ADVISE_NO_CACHE
           whether to remove each chunk from page when closing it to reduce cache pressure
           generated by chunkserver (default is 1, i.e. yes)

       HDD_PUNCH_HOLES
           if enabled then chunkserver detects zero values in chunk data and frees corresponding
           file blocks (decreasing file system usage). This option works only on Linux with file
           systems supporting punching holes (XFS, ext4, Btrfs, tmpfs) (default is 1, i.e. yes)

       ENABLE_LOAD_FACTOR
           if enabled, chunkserver will send periodical reports of its I/O load to master, which
           will be taken into consideration when picking chunkservers for I/O operations.

       REPLICATION_BANDWIDTH_LIMIT_KBPS
           limit how many kilobytes can be replicated from other chunkservers to this chunkserver
           in every second (by default undefined, i.e. no limits)

       NR_OF_NETWORK_WORKERS
           number of threads which handle (in a round-robin manner) connections with clients
           (default is 1); these threads are responsible for reading from sockets and coping data
           from internal buffers to sockets

       NR_OF_HDD_WORKERS_PER_NETWORK_WORKER
           number of threads that each network worker may use to do disk operations like opening
           chunks, reading or writing them (default is 2)

       READ_AHEAD_KB
           additional number of kilobytes which should be passed to
           posix_fadvise(POSIX_FADV_WILLNEED) before reading data from a chunk (default is 0,
           i.e. use posix_fadvise only with the amount of data that is really needed; the value
           is aligned down to 64 KiB)

       MAX_READ_BEHIND_KB
           try to fix out-of-order read requests; the value tells how much of skipped data to
           read if an offset of some read operation is greater than the offset where the previos
           operation finished (default is 0, i.e. don’t read any skipped data; the value is
           aligned down to 64 KiB)

       CREATE_NEW_CHUNKS_IN_MOOSEFS_FORMAT
           whether to create new chunks in the MooseFS format (signature + <checksum>* + <data
           block>*) or in the newer interleaved format ([<checksum> <data block>]*). (Default is
           1, i.e. new chunks are created in MooseFS format)

       PERFORM_FSYNC
           call fsync() after a chunk is modified (default is 1, i.e. enabled)

       REPLICATION_TOTAL_TIMEOUT_MS
           total timeout for single replication operation. Replications that take longer than
           that are considered failed and are immediately aborted (default: 60000)

       REPLICATION_CONNECTION_TIMEOUT_MS
           connection for single replication operation. If connecting to another chunkserver
           takes longer than this timeout, the operation is considered failed and is immediately
           aborted (default: 1000)

       REPLICATION_WAVE_TIMEOUT_MS, ADVANCED
           timeout for single wave in replication. After this timeout, next wave of read requests
           is sent to other chunkservers (default: 500)

COPYRIGHT

       Copyright 2008-2009 Gemius SA, 2013-2015 Skytechnology sp. z o.o.

       LizardFS 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 3.

       LizardFS 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 LizardFS. If
       not, see http://www.gnu.org/licenses/.

SEE ALSO

       mfschunkserver(8), mfshdd.cfg(5)

                                            01/11/2020                      MFSCHUNKSERVER.CFG(5)