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mfsmount - Man Page

mount Lizard File System


mfsmount mountpoint [-d] [-f] [-s] [-m] [-n] [-p]
         [-H HOST] [-P PORT] [-S PATH] [-o opt[,opt]...]
mfsmount -h|--help
mfsmount -V|--version


Mount Lizard File System.

General options:

-h,  --help

display help and exit


display version information and exit

FUSE options:

-d, -o debug

enable debug mode (implies -f)


foreground operation


disable multi-threaded operation

LizardFS options:

-c CFGFILE, -o mfscfgfile=CFGFILE

loads file with additional mount options

-m, --meta, -o mfsmeta

mount MFSMETA companion filesystem instead of primary LizardFS


omit default mount options (-o allow_other,default_permissions)

-p, -o askpassword

prompt for password (interactive version of -o mfspassword=PASS)

-H HOST, -o mfsmaster=HOST

connect with LizardFS master on HOST (default is mfsmaster)

-P PORT, -o mfsport=PORT

connect with LizardFS master on PORT (default is 9421)

-B HOST, -o mfsbind=HOST

local address to use for connecting with master instead of default one

-S PATH, -o mfssubfolder=PATH

mount specified LizardFS directory (default is /, i.e. whole filesystem)

-o enablefilelocks=[0,1]

enables/disables global file locking (disabled by default)

-o mfspassword=PASSWORD

authenticate to LizardFS master with PASSWORD

-o mfsmd5pass=MD5

authenticate to LizardFS master using directly given MD5 (only if mfspassword option is not specified)

-o mfsdelayedinit

connection with master is done in background - with this option mount can be run without network (good for being run from fstab / init scripts etc.)

-o mfsacl

enable ACL support (disabled by default)

-o mfsaclcacheto=SEC

set ACL cache timeout in seconds (default: 1.0)

-o mfsaclcachesize=N

define ACL cache size in number of entries (0: no cache; default: 1000)

-o mfsrwlock=0|1

when set to 1, parallel reads from the same descriptor are performed (default: 1)

-o mfsmkdircopysgid=N

sgid bit should be copied during mkdir operation (on linux default: 1, otherwise: 0)

-o mfssugidclearmode=SMODE

set sugid clear mode (see below)

-o mfsdebug

print some LizardFS-specific debugging information

-o mfscachemode=CACHEMODE

set cache mode (see Data Cache Modes; default is AUTO)

-o mfscachefiles

(deprecated) preserve file data in cache (equivalent to -o mfscachemode=YES)

-o mfsattrcacheto=SEC

set attributes cache timeout in seconds (default: 1.0)

-o mfsentrycacheto=SEC

set file entry cache timeout in seconds (default: 0.0, i.e. no cache)

-o mfsdirentrycacheto=SEC

set directory entry cache timeout in seconds (default: 1.0)

-o mfswritecachesize=N

specify write cache size in MiB (in range: 16..2048 - default: 128)

-o mfscacheperinodepercentage=N

specify what part of the write cache non occupied by other inodes can a single inode occupy (measured in %). E.g. When N=75 and the inode X uses 10 MiB, and all other inodes use 20 MiB out of 100 MiB cache, X can use 50 MiB more (since 75% of 80 MiB is 60 MiB). Default: 25.

-o mfschunkserverreadto=MSEC

set timeout for whole communication with a chunkserver during read operation in milliseconds (default: 2000)

-o mfschunkserverwriteto=MSEC

set chunkserver response timeout during write operation in milliseconds (default: 5000)

-o mfschunkserverrtt=MSEC

set timeout after which SYN packet is considered lost during the first retry of connecting a chunkserver (default: 200)

-o mfschunkserverconnectreadto=MSEC

set timeout for connecting with chunkservers during read operation in milliseconds (default: 2000)

-o mfschunkserverwavereadto=MSEC

set timeout for executing each wave of a read operation in milliseconds (default: 500)

-o mfschunkservertotalreadto=MSEC

set timeout for the whole communication with chunkservers during a read operation in milliseconds (default: 2000)

-o cacheexpirationtime=MSEC

set timeout for read cache entries to be considered valid in milliseconds (0 disables cache) (default: 300)

-o readaheadmaxwindowsize=KB

set max value of readahead window per single descriptor in kibibytes (default: 16384)

-o mfsrlimitnofile=N

try to change limit of simultaneously opened file descriptors on startup (default: 100000)

-o mfsnice=LEVEL

try to change nice level to specified value on startup (default: -19)

-o mfswriteworkers=N

define number of write workers (default: 10)

-o mfswritewindowsize=N

define write window size (in blocks) for each chunk (default: 15)

-o mfsmemlock

try to lock memory (must be enabled at build time)

-o mfsdonotrememberpassword

do not remember password in memory - more secure, but when session is lost then new session is created without password

-o mfsioretries=N

specify number of retries before I/O error is returned (default: 30)

-o mfsreportreservedperiod=N

specify interval of reporting reserved inodes in seconds (default: 60)

-o mfsiolimits=PATH

specify local I/O limiting configuration file (default: no I/O limiting)

General mount options (see mount(8) manual):

-o rw|-o ro

Mount file-system in read-write (default) or read-only mode respectively.

-o suid|-o nosuid

Enable or disable suid/sgid attributes to work.

-o dev|-o nodev

Enable or disable character or block special device files interpretation.

-o exec|-o noexec

Allow or disallow execution of binaries.

-o symlinkcachetimeout=N

Set timeout value for symlink cache timeout in seconds. Default value is 3600.

-o bandwidthoveruse=N

Define ratio of allowed bandwidth overuse when fetching data. Default value is 1.0. This option is effective only with N+M goals (xors and erasure codes).

Data Cache Modes

There are three cache modes: NO, YES and AUTO. Default option is AUTO and you shuldn’t change it unless you really know what you are doing. In AUTO mode data cache is managed automatically by mfsmaster.


never allow files data to be kept in cache (safest but can reduce efficiency)


always allow files data to be kept in cache (dangerous)


file cache is managed by mfsmaster automatically (should be very safe and efficient)

Sugid Clear Mode

SMODE can be set to:

SMODE extra info:

btrfs,ext2,ext3,ext4,hfs[+],jfs,ntfs and reiserfs on Linux work as EXT.

Only xfs on Linux works a little different. Beware that there is a strange operation - chown(-1,-1) which is usually converted by a kernel into something like chmod ug-s, and therefore can’t be controlled by MFS as chown

Reporting Bugs

Report bugs to <contact@lizardfs.org>.

See Also

mfsmaster(8), mfstools(1), moosefs(7), mount(8)

Referenced By

lizardfs(1), lizardfs(7), mfschunkserver(8), mfsmaster(8), mfsmount.cfg(5).