Mirroring across Targets, Controllers or Enclosures

To create a volume whose mirrored data plexes lie on different controllers, you can use either of the commands described in this section.

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

The attribute mirror=target specifies that volumes should be mirrored between identical target IDs on different controllers.

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

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

# vxassist make volspec 10g layout=mirror nmirror=2 mirror=ctlr \
  ctlr:c2 ctlr:c3
# vxassist make volspec 10g layout=mirror nmirror=2 mirror=ctlr \
  ctlr:scsi2 ctlr:scsi3

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 make 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.

See “Specifying Ordered Allocation of Storage to Volumes” for a description of other ways in which you can control how volumes are laid out on the specified storage.