mfsmount - mount a LizardFS 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


General options

-h, --help display help and exit
-V display version information and exit

FUSE options

-d, -o debug enable debug mode (implies -f)
-f foreground operation
-s disable multi-threaded operation

LizardFS options

-m, --meta, -o mfsmeta
 mount MFSMETA companion filesystem instead of primary LizardFS
-c CFGFILE, -o mfscfgfile=CFGFILE
loads file with additional mount options
-n 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 running 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 o operation in milliseconds (default: 2000)
-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 1.25. This option is effective only with N+M goals (xors and erasure codes).


Mount a LizardFS Filesystem


There are three cache modes: NO, YES and AUTO. The 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)


SMODE can be set to:

MFS will not change suid and sgid bit on chown
clear suid and sgid on every chown - safest operation
standard behavior in OS X and Solaris (chown made by unprivileged user clear suid and sgid)
standard behavior in BSD systems (like in OSX, but only when something is really changed)
standard behavior in most file systems on Linux (directories not changed, others: suid cleared always, sgid only when group exec bit is set)
standard behavior in XFS on Linux (like EXT but directories are changed by unprivileged users)

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’


Report bugs to <>.


mfsmaster(8), lizardfs(1), lizardfs(7), mount(8)