HP Veritas Volume Manager 5.0 -UX 11i v3 Use, vol1, mydg, fsck, snapdg, ACTIVE, vxsnap, volume, command, snapvol, prepsnap, mysnapdg, snapshot, break-off, diskgroup, diskgroup, snapdiskgroup

332Administering volume snapshots

Creating instant snapshots

[mirdg=snapdg]

The optional mirdg attribute can be used to specify the snapshot volume’s current disk group, snapdg. The -boption can be used to perform the synchronization in the background. If the -boption is not specified, the command does not return until the link becomes ACTIVE.

For example, the following command links the prepared volume, prepsnap, in the disk group, mysnapdg, to the volume, vol1, in the disk group, mydg:

#vxsnap -g mydg -b addmir vol1 mirvol=prepsnap \ mirdg=mysnapdg

If the -boption is specified, you can use the vxsnap snapwait command to wait for the synchronization of the linked snapshot volume to complete, as shown in this example:

#vxsnap -g mydg snapwait vol1 mirvol=prepsnap \ mirdg=mysnapvoldg

2To create a linked break-off snapshot, use the following form of the vxsnap make command.

#vxsnap [-g diskgroup] make source=volume/snapvol=snapvol\ [/snapdg=snapdiskgroup]

The snapdg attribute must be used to specify the snapshot volume’s disk group if this is different from that of the data volume.

For example, to use the prepared volume, prepsnap, as the snapshot for the volume, vol1, in the disk group, mydg, use the following command:

#vxsnap -g mydg make \ source=vol1/snapvol=prepsnap/snapdg=mysnapdg

3Use fsck (or some utility appropriate for the application running on the volume) to clean the temporary volume’s contents. For example, you can use this command with a VxFS file system:

# fsck -F vxfs /dev/vx/rdsk/diskgroup/snapshot

4If you require a backup of the data in the snapshot, use an appropriate utility or operating system command to copy the contents of the snapshot to tape, or to some other backup medium.

5You now have the following choices of what to do with a linked break-off snapshot:

■Refresh the contents of the snapshot. This creates a new point-in-time image of the original volume ready for another backup. If synchronization was already in progress on the snapshot, this operation may result in large portions of the snapshot having to be resynchronized. See “Refreshing an instant snapshot” on page 337 for details.