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)