vxsmptadm - administer VxVM snappoints
vxsnptadm [-g diskgroup] create
vol [snptname=snpt] [snapvolname=snapvol]
[vol2 [snptname=snpt2] [snapvolname=snapvol2]
vxsnptadm [-g diskgroup] info vol [snptname=snpt]
vxsnptadm [-g diskgroup] remove vol snptname=snpt
vxsnptadm [-g diskgroup] removeall vol [cookie=cookie]
vxsnptadm [-g diskgroup] rename vol snptname=snpt newname=snpt2
vxsnptadm [-g diskgroup] set nodata vol snptname=snpt
The vxsnptadm utility performs administrative tasks, such as creation, deletion, and conversion, on a snappoint (snpt) of a specified VxVM volume (vol).
Note: Snappoint names cannot be longer than 128 characters.
A snappoint is a VxVM object that provides information about the changes to a volume relative its contents at a given point in time. Snappoints use the instant snapshot feature of VxVM, and are intended to be used with backup applications.
Two kinds of snappoint are supported:
o A dataful snappoint (created by specifying data=yes to the vxsnptadm create command) uses an instant (copy-on-write) snapshot to record the contents of the volume at the time that the snappoint was taken. o A nodata snappoint (created by specifying data=no to the vxsnptadm create command) tracks changes to the regions of a volume since the snappoint was taken. These changes are stored in a bitmap. It does not record volume data.
Snappoints are supported on shared volumes in a VxVM cluster.
Snappoints are immediately available for use on being created, and they are persistent across system reboots and cluster restarts.
create Creates one or more snappoints on a volume. If the name of the snappoint is not specified using the snptname attribute, a default name of the form SNPTnumber-vol is used, where vol is the name of the original volume. If the name of the instant snapshot volume is not specified using the snapvolname attribute, a default name is taken using the definition of the snapvol attribute in the defaults file, /etc/default/vxsnpt. (For example, the entry snapvol=vol1/snapvol1 defines snapvol1 as the default name for the snapshot volume of vol1.) The operation fails if snapvolname is not specified, and no defaults file exists. The cookie is optional, but if specified, the same value must be entered for the remove and removeall operations. The value that is assigned to the data attribute specifies whether a dataful (data=yes) or a nodata (data=no) snappoint is to be created. By default, a dataful snappoint is created if this attribute is not specified. Note: The snapshot volumes must be created in advance of running this command. info Displays information about a snappoint including the name of its parent volume, associated instant snapshot, creation time, flags, comments and cookie. remove Removes a snappoint from a volume. removeall Removes all snappoints from a volume. rename Renames a snappoint of the volume vol specified by the snptname attribute with the name specified by the newname attribute. set Sets the attributes of a snappoint. The attribute nodata sets the NODATA flag on a snappoint. If the NODATA flag is not set, the snappoint is dataful.
-g diskgroup Specifies the disk group in which to apply the requested operation. If not specified, the default disk group is assumed (see vxdg(1M) for more information).
Create a full-sized instant snapshot volume that is to be used with the snappoint:
vxsnap -g mydg make source=vol1/snapvol=snapvol1
Note: This form of the vxsnap command requires that the volume specified by snapvol must be prepared in advance, as described in the vxsnap(1M) manual page.
The following command creates a nodata snappoint named friday_7pm for the volume vol1 in the disk group mydg:
vxsnptadm -g mydg create vol1 snptname=friday_7pm data=no cookie=FOO
This example assumes that the /etc/default/vxsnpt file contains the entry snapvol=vol1/snapvol1.
List information about the snappoints that are associated with volume vol1:
# vxsnptadm -g mydg info vol1 VOLUME SNAPPOINT SNAPSHOT-VOLUME CREATION-TIME vol1 monday_7pm SNAP1-vol1 Mon Mar 3 19:00:12 2003 vol1 friday_7pm SNAP2-vol1 Fri Mar 7 19:00:27 2003
Remove the snappoint monday_7pm from volume vol1:
vxsnptadm -g mydg remove vol1 snptname=monday_7pm cookie=FOO
Create a snappoint named tuesday_7pm on each of the volumes vol2, vol3 and vol4, explicitly specifying the snapshot volume names:
vxsnptadm -g mydg create \ vol2 snptname=tuesday_7pm snapvolname=snapvol2 \ vol3 snptname=tuesday_7pm snapvolname=snapvol3 \ vol4 snptname=tuesday_7pm snapvolname=snapvol4
|VxVM 4.0||vxsnptadm (1M)|