Symantec logo

Unrelocation of subdisks to a replacement boot disk

When a boot disk is encapsulated, the root file system and other system areas, such as the swap partition, are made into volumes. VxVM creates a private region using part of the existing swap area, which is usually located in the middle of the disk. However, when a disk is initialized as a VM disk, VxVM creates the private region at the beginning of the disk.

If a mirrored encapsulated boot disk fails, hot-relocation creates new copies of its subdisks on a spare disk. The name of the disk that failed and the offsets of its component subdisks are stored in the subdisk records as part of this process. After the failed boot disk is replaced with one that has the same storage capacity, it is "initialized" and added back to the disk group. vxunreloc can be run to move all the subdisks back to the disk. However, the difference of the disk layout between an initialized disk and an encapsulated disk affects the way the offset into a disk is calculated for each unrelocated subdisk. Use the -f option to vxunreloc to move the subdisks to the disk, but not to the same offsets. For this to be successful, the replacement disk should be at least 2 megabytes larger than the original boot disk.

vxunreloc makes the new disk bootable after it moves all the subdisks to the disk.

The system dump device is usually configured to be the swap partition of the root disk. Whenever a swap subdisk is moved (by hot-relocation, or using vxunreloc) from one disk to another, the dump device must be re-configured on the new disk.

You can use the dumpadm command to view and set the dump device.

See the dumpadm(1M) manual page.