288Administering volumes

Setting tags on volumes

Note: The vxvol set len command cannot increase the size of a volume unless the needed space is available in the plexes of the volume. When the size of a volume is reduced using the vxvol set len command, the freed space is not released into the disk group’s free space pool.

If a volume is active and its length is being reduced, the operation must be forced using the -o force option to vxvol. This prevents accidental removal of space from applications using the volume.

The length of logs can also be changed using the following command:

#vxvol [-gdiskgroup] set loglen=length log_volume

Note: Sparse log plexes are not valid. They must map the entire length of the log. If increasing the log length would make any of the logs invalid, the operation is not allowed. Also, if the volume is not active and is dirty (for example, if it has not been shut down cleanly), the log length cannot be changed. This avoids the loss of any of the log contents (if the log length is decreased), or the introduction of random data into the logs (if the log length is being increased).

Setting tags on volumes

Volume tags are used to implement the Dynamic Storage Tiering feature of the Storage Foundation software. For more information about this feature, see the Veritas File System Administrator’s Guide.

You can use the following forms of the vxassist command to set a named tag and optional tag value on a volume, to replace a tag, and to remove a tag from a volume:

#vxassist [-gdiskgroup] settag volume tagname[=tagvalue]

#vxassist [-gdiskgroup] replacetag volume oldtag newtag

#vxassist [-g diskgroup] removetag volume tagname

To list the tags that are associated with a volume, use this command:

#vxassist [-g diskgroup] listtag volume

To list the volumes that have a specified tag name, use this command:

#vxassist [-g diskgroup] list tag=tagname volume

Tag names and tag values are case-sensitive character strings of up to 256 characters. Tag names can consist of letters (A through Z and a through z), numbers (0 through 9), dashes (-), underscores (_) or periods (.) from the ASCII character set. A tag name must start with either a letter or an underscore. Tag values can consist of any character from the ASCII character set with a decimal value from 32 through 127. If a tag value includes any spaces, quote the specification to protect it from the shell, as shown here: