extendfs - Extends UFS file systems
/sbin/extendfs [- s] [disk_blocks] device_name
Use the extendfs command to increase the storage space in a UFS file sys-
tem. 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 -o extend option.
The procedure for increasing the storage space of a UFS file system is as
1. Look at the contents the /etc/fstab file to identify the disk parti-
tion that maps to the file system.
2. Ensure that there is available storage space on the target disk as
a. 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
b. If LSM is not in use on your system, use the disklabel command or
the diskconfig graphical user interface to check the current size
and use of partitions on the disk.
3. 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
4. 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 parti-
tion by an equivalent number.
5. 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
6. 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 methods.
+ To extend the file system to use all the available space, you
specify the disk partition on which the file system resides, as
# extendfs /dev/disk/dsk4g
+ To extend the file system to use only part of the available
space, you specify a number of disk blocks, as follows:
# extendfs -s 300000 /dev/disk/dsk4g
The remainder of the extended partion is reserved for future use.
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 available space.
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 command.
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
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 information on
Specifies the command path.
diskconfig(8), disklabel(8), mount(8), and fstab(4).