mkfs.gfs2(8) System Manager's Manual mkfs.gfs2(8)
NAME
mkfs.gfs2 - Make a GFS2 filesystem
SYNOPSIS
mkfs.gfs2 [OPTION]... DEVICE [ block-count ]
DESCRIPTION
mkfs.gfs2 is used to create a Global File System.
OPTIONS
-b BlockSize
Set the filesystem block size to BlockSize (must be a power of two). The minimum block size is 512. The FS block size cannot
exceed the machine's memory page size. On the most architectures (i386, x86_64, s390, s390x), the memory page size is 4096 bytes.
On other architectures it may be bigger. The default block size is 4096 bytes. In general, GFS2 filesystems should not deviate
from the default value.
-c MegaBytes
Initial size of each journal's quota change file
-D Enable debugging output.
-h Print out a help message describing available options, then exit.
-J MegaBytes
The size of the journals in Megabytes. The default journal size is 128 megabytes. The minimum size is 8 megabytes.
-j Number
The number of journals for gfs2_mkfs to create. You need at least one journal per machine that will mount the filesystem. If this
option is not specified, one journal will be created.
-K Keep, do not attempt to discard blocks at mkfs time (discarding blocks initially is useful on solid state devices and sparse /
thin-provisioned storage).
-O This option prevents gfs2_mkfs from asking for confirmation before writing the filesystem.
-o Specify extended options. Multiple options can be separated by commas. Valid extended options are:
help Display an extended options help summary, then exit.
sunit=bytes
This is used to specify the stripe unit for a RAID device or striped logical volume. This option ensures that resource
groups will be stripe unit aligned and overrides the stripe unit value obtained by probing the device. This value must be
a multiple of the file system block size and must be specified with the swidth option.
swidth=bytes
This is used to specify the stripe width for a RAID device or striped logical volume. This option ensures that resource
groups will be stripe aligned and overrides the stripe width value obtained by probing the device. This value must be a
multiple of the sunit option and must also be specified with it.
align=[0|1]
Disable or enable the alignment of resource groups. The default behaviour is to align resource groups to the stripe width
and stripe unit values obtained from probing the device or specified with the swidth and sunit extended options.
-p LockProtoName
LockProtoName is the name of the locking protocol to use. Acceptable locking protocols are lock_dlm (for shared storage) or if
you are using GFS2 as a local filesystem (1 node only), you can specify the lock_nolock protocol. If this option is not specified,
lock_dlm protocol will be assumed.
-q Be quiet. Don't print anything.
-r MegaBytes
gfs2_mkfs will try to make Resource Groups about this big. Minimum RG size is 32 MB. Maximum RG size is 2048 MB. A large RG size
may increase performance on very large file systems. If not specified, mkfs.gfs2 will choose the RG size based on the size of the
file system: average size file systems will have 256 MB RGs, and bigger file systems will have bigger RGs for better performance.
-t LockTableName
The lock table field appropriate to the lock module you're using. It is clustername:fsname. Clustername must match that in clus-
ter.conf; only members of this cluster are permitted to use this file system. Fsname is a unique file system name used to distin-
guish this GFS2 file system from others created (1 to 16 characters). Lock_nolock doesn't use this field. Valid clusternames and
fsnames may only contain alphanumeric characters, hyphens (-) and underscores (_).
-V Print program version information, then exit.
[ block-count ]
Make the file system this many blocks in size. If not specified, the entire length of the specified device is used.
EXAMPLE
gfs2_mkfs -t mycluster:mygfs2 -p lock_dlm -j 2 /dev/vg0/mygfs2
This will make a Global File System on the block device "/dev/vg0/mygfs2". It will belong to "mycluster" and register itself as
wanting locking for "mygfs2". It will use DLM for locking and make two journals.
gfs2_mkfs -t mycluster:mygfs2 -p lock_nolock -j 3 /dev/vg0/mygfs2
This will make a Global File System on the block device "/dev/vg0/mygfs2". It will belong to "mycluster" and but have no cluster
locking. It will have three journals.
mkfs.gfs2(8)