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. On a trans metadevice, the master device is expanded, not the trans metadevice. Then the growfs command is run on the trans metadevice. (You can add space to a logging device, but you do not need to run the growfs command. The new space is automatically recognized.)
growfs will ``write-lock'' (see lockfs) 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.
# metainit -f d8 2 1 c1t0d0s3 1 c2t0d0s3
# umount /export
(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
This 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.
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.
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.
Solstice DiskSuite User's Guide, Solstice DiskSuite Reference