growfs(1M) (man pages section 1M: System Administration Commands)

man pages section 1M: System Administration Commands

growfs(1M)

Name

growfs– non-destructively expand a UFS file system

Synopsis

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

Description

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.

Options

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.
newfs-options: The options are documented in the newfs man page.
raw-device: 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.

Examples

Example 1 Expanding nonmetadevice slice for `/export` file system

The following example expands a nonmetadevice slice for the /export file system. In this example, the existing slice, /dev/dsk/c1t0d0s3, is converted to a metadevice so additional slices can be concatenated.

# metainit -f d8 2 1 c1t0d0s3 1 c2t0d0s3
# umount /export

Example 2 Associate `/export` with new metadevice

Edit the /etc/vfstab file to change the entry for /export to the newly defined metadevice, d8.

# mount /export
# growfs -M /export /dev/md/rdsk/d8

The first example starts by running the metainit command with the -f option to force the creation of a new concatenated metadevice d8, which consists of the existing slice /dev/dsk/c1t0d0s3 and a new slice /dev/dsk/c2t0d0s3. Next, the file system on /export must be unmounted. The /etc/vfstab file is edited to change the entry for /export to the newly defined metadevice name, rather than the slice name. After the file system is remounted, the growfs command is run to expand the file system. The file system will span the entire metadevice when growfs completes. The -M option enables the growfs command to expand a mounted file system. During the expansion, write access for /export is suspended until growfs unlocks the file system. Read access is not affected, though access times are not kept when the lock is in effect.

Example 3 Dynamic Expansion of `/export` file system

The following example picks up from the previous one. Here, the /export file system mounted on metadevice d8 is dynamically expanded.

# metattach d8 c0t1d0s2
# growfs -M /export /dev/md/rdsk/d8

This example begins by using the metattach command to dynamically concatenate a new slice, /dev/dsk/c0t1d0s2, to the end of an existing metadevice, d8. Next, the growfs command specifies that the mount-point is /export and that it is to be expanded onto the raw metadevice /dev/md/rdsk/d8. The file system will span the entire metadevice when growfs completes. During the expansion, write access for /export is suspended until growfs unlocks the file system. Read access is not affected, though access times are not kept when the lock is in effect.

Example 4 Expanding mounted file system to existing mirror

The following example expands a mounted file system /files, to an existing mirror, d80, which contains two submirrors, d9 and d10.

# metattach d9 c0t2d0s5
# metattach d10 c0t3d0s5
# growfs -M /files /dev/md/rdsk/d80

In this example, the metattach command dynamically concatenates the new slices to each submirror. The metattach command must be run for each submirror. The mirror will automatically grow when the last submirror is dynamically concatenated. The mirror will grow to the size of the smallest submirror. The growfs command then expands the file system. The growfs command specifies that the mount-point is /files and that it is to be expanded onto the raw metadevice /dev/md/rdsk/d80. The file system will span the entire mirror when the growfs command completes. During the expansion, write access for the file system is suspended until growfs unlocks the file system. Read access is not affected, though access times are not kept when the lock is in effect.

Exit Status

The following exit values are returned:

0: Successful completion.
>0: An error occurred.

Attributes

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Availability	SUNWmdu

LIMITATIONS

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.

SunOS 5.11 Last Revised 20 Apr 2009