HP Veritas Volume Manager 5.0 -UX 11i v3 Mirroring across targets, controllers or enclosures

Creating volumes

Mirroring across targets, controllers or enclosures

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for the attribute stripe-mirror-col-split-trigger-ptthat is defined in the vxassist defaults file.

If there are multiple subdisks per column, you can choose to mirror each subdisk individually instead of each column. To mirror at the subdisk level, specify the layout as stripe-mirror-sdrather than stripe-mirror. To mirror at the column level, specify the layout as stripe-mirror-colrather than stripe-

mirror.

Mirroring across targets, controllers or enclosures

To create a volume whose mirrored data plexes lie on different controllers (also known as disk duplexing) or in different enclosures, use the vxassist command as described in this section.

In the following command, the attribute mirror=target specifies that volumes should be mirrored between identical target IDs on different controllers.

#vxassist [-b] [-g diskgroup] make volume length \ layout=layout mirror=target [attributes]

The attribute mirror=ctlr specifies that disks in one mirror should not be on the same controller as disks in other mirrors within the same volume:

#vxassist [-b] [-g diskgroup] make volume length \ layout=layout mirror=ctlr [attributes]

Note: Both paths of an active/passive array are not considered to be on different controllers when mirroring across controllers.

The following command creates a mirrored volume with two data plexes in the disk group, mydg:

#vxassist -b -g mydg make volspec 10g layout=mirror nmirror=2 \ mirror=ctlr ctlr:c2 ctlr:c3

The disks in one data plex are all attached to controller c2, and the disks in the other data plex are all attached to controller c3. This arrangement ensures continued availability of the volume should either controller fail.

The attribute mirror=enclr specifies that disks in one mirror should not be in the same enclosure as disks in other mirrors within the same volume.

The following command creates a mirrored volume with two data plexes:

#vxassist -b make -g mydg volspec 10g layout=mirror nmirror=2 \ mirror=enclr enclr:enc1 enclr:enc2

The disks in one data plex are all taken from enclosure enc1, and the disks in the other data plex are all taken from enclosure enc2. This arrangement ensures continued availability of the volume should either enclosure become unavailable.