A.2.7.4 Using Hot-Relocation

Hot-relocation is the ability of a system to automatically react to I/O failures on redundant (mirrored or RAID5) volume manager objects, and to restore redundancy and access to those objects. Hot-relocation is supported only on configurations using SSVM. SSVM detects I/O failures on volume manager objects and relocates the affected subdisks to disks designated as spare disks or free space within the disk group. SSVM then reconstructs the objects that existed before the failure and makes them redundant and accessible again.

When a partial disk failure occurs (that is, a failure affecting only some subdisks on a disk), redundant data on the failed portion of the disk is relocated, and the existing volumes consisting of the unaffected portions of the disk remain accessible.

Hot-relocation is performed only for redundant (mirrored or RAID5) subdisks on a failed disk. Non-redundant subdisks on a failed disk are not relocated, but you are notified of their failure.

A spare disk must be initialized and placed in a disk group as a spare before it can be used for replacement purposes. If no disks have been designated as spares when a failure occurs, SSVM automatically uses any available free space in the disk group in which the failure occurs. If there is not enough spare disk space, a combination of spare space and free space is used. You can designate one or more disks as hot-relocation spares within each disk group. Disks can be designated as spares with the vxedit(1M) command.