extendfs(8)extendfs(8)NAMEextendfs - Extends UFS file systems
/sbin/extendfs [-s disk_blocks] device_name
Specifies the total number of 512-byte blocks for the UFS file system.
This value is not an increment. Specifying a value with this
option does not increment the file system by that value; rather,
it is the new size of the file system.
Use the extendfs command to increase the storage space in a UFS file
system. The file system must not be mounted when you perform this
operation. To extend a mounted (in use) UFS file system, use the mount
command with the -u -o extend mnt_point parameters.
The procedure for increasing the storage space of a UFS file system is
as follows: Look at the contents of the /etc/fstab file to identify the
disk partition that maps to the file system. Ensure that there is
available storage space on the target disk as follows: If LSM is in use
on your system, use LSM commands to increase the size of the LSM volume
as described in the Logical Storage Manager guide. If LSM is not in
use on your system, use the disklabel command or the diskconfig graphi‐
cal user interface to check the current size and use of partitions on
the disk. If there is adequate space on an adjacent partition, use the
disklabel command to write the current label to a file as follows: #
disklabel -r dsk4 > d4label Edit the disklabel file to change the size
of the partition on which your UFS file system resides. Increase the
number of disk blocks on the partition and decrease the disk block size
of the adjacent partition by an equivalent number. Use the disklabel
command with the -R option to write the revised label to the raw disk
as follows: # disklabel -R /dev/rdisk/dsk4 d4label When the disk label
is revised, extend the file system using the extendfs command. You can
either use the full extent of the newly sized partition or extend the
file system in stages. The following example commands show both meth‐
ods. To extend the file system to use all the available space, you
specify the disk partition on which the file system resides, as fol‐
lows: # extendfs /dev/disk/dsk4g To extend the file system to use only
part of the available space, you specify the total number of disk
blocks to be used, as follows: # extendfs-s 300000 /dev/disk/dsk4g
The remainder of the extended partion is reserved for future
You can extend a file system as many times as necessary, up to the
physical limit of the storage device. When no more space is available
on the storage device, you must back up the file system using the dump
command and restore the file system to a storage device that has more
Once you have extended a file system, the operation cannot be reversed
except by a back up and restore operation. Use the dump command to back
up the file system. You can then reset the partition sizes manually
and restore the file system to the storage device.
The disklabel command produces output similar to that of the newfs com‐
mand. If a list of disk blocks is not displayed on the terminal, the
command has failed. Verify the partition settings and the mount status
of the target file system.
The disklabel command does not permit you to overwrite a partition if
it is in use. Refer to the disklabel(8) reference page for more infor‐
mation on label errors.
Specifies the command path.
RELATED INFORMATIONdiskconfig(8), disklabel(8), mount(8), and fstab(4).