Veritas Volume Manager 5.0.1 Administrator's Guide, HP-UX 11i v3, First Edition, November 2009

To create a third-mirror break-off snapshot, use the following form of the

vxsnap make command.

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

{/plex=plex1[,plex2,...]|/nmirror=number]}

Either of the following attributes may be specified to create the new snapshot

volume, snapvol, by breaking off one or more existing plexes in the original

volume:

Specifies the plexes in the existing volume that are to be broken

off. This attribute can only be used with plexes that are in the

ACTIVE state.

plex

Specifies how many plexes are to be broken off. This attribute

can only be used with plexes that are in the SNAPDONE state.

(Such plexes could have been added to the volume by using the

vxsnap addmir command.)

nmirror

Snapshots that are created from one or more ACTIVE or SNAPDONE plexes in

the volume are already synchronized by definition.

For backup purposes, a snapshot volume with one plex should be sufficient.

For example, to create the instant snapshot volume, snap2myvol, of the

volume, myvol, in the disk group, mydg, from a single existing plex in the

volume, use the following command:

# vxsnap -g mydg make source=myvol/newvol=snap2myvol/nmirror=1

The next example shows how to create a mirrored snapshot from two existing

plexes in the volume:

# vxsnap -g mydg make source=myvol/newvol=snap2myvol/plex=myvol-03,myvol-04

Use 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

The specified device must have a valid entry in the /etc/fstab file.

To backup 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.

You now have the following options:

377Administering volume snapshots

Creating instant snapshots