GROWFS(1M) Maintenance Commands GROWFS(1M)

growfs - non-destructively expand a UFS file system

/usr/sbin/growfs [-M mount-point] [newfs-options]

growfs non-destructively expands a mounted or unmounted UNIX file system (UFS) to the size of the file system's slice(s).

Typically, disk space is expanded by first adding a slice to a metadevice, then running the growfs command. When adding space to a mirror, you expand each submirror before expanding the file system.

growfs will ``write-lock'' (see lockfs(1M)) a mounted file system when expanding. The length of time the file system is write-locked can be shortened by expanding the file system in stages. For instance, to expand a 1 Gbyte file system to 2 Gbytes, the file system can be grown in 16 Mbyte stages using the -s option to specify the total size of the new file system at each stage. The argument for -s is the number of sectors, and must be a multiple of the cylinder size. Note: The file system cannot be grown if a cylinder size of less than 2 is specified. Refer to the newfs(1M) man page for information on the options available when growing a file system.

growfs displays the same information as mkfs during the expansion of the file system.

If growfs is aborted, recover any lost free space by unmounting the file system and running the fsck command, or run the growfs command again.

Note: If growfs is aborted and the file system is used before fsck is run on it, UFS metadata might be left in an incomplete state, with the result that the file system would be corrupted. In such a circumstance, you would have to restore the file system from backups.

Root privileges are required for all of the following options.

-M mount-point

The file system to be expanded is mounted on mount-point. File system locking (lockfs) will be used.


The options are documented in the newfs man page.


Specifies the name of a raw metadevice or raw special device, residing in /dev/md/rdsk, or /dev/rdsk, respectively, including the disk slice, where you want the file system to be grown.

The following exit values are returned:


Successful completion.


An error occurred.

fsck(1M), lockfs(1M), mkfs(1M), newfs(1M), attributes(5)

Only UFS file systems (either mounted or unmounted) can be expanded using the growfs command. Once a file system is expanded, it cannot be decreased in size. The following conditions prevent you from expanding file systems: When acct is activated and the accounting file is on the target device. When C2 security is activated and the logging file is on the target file system. When there is a local swap file in the target file system. When the file system is root (/), /usr, or swap.
April 20, 2009 OmniOS