Veritas Volume Manager 5.0.1 Administrator's Guide, HP-UX 11i v3, First Edition, November 2009

This is normally detected as a result of an I/O failure from a VxVM
object. VxVM attempts to correct the error. If the error cannot be
corrected, VxVM tries to access configuration information in the
private region of the disk. If it cannot access the private region, it
considers the disk failed.
Disk failure
This is normally detected as a result of an uncorrectable I/O error in
the plex (which affects subdisks within the plex). For mirrored volumes,
the plex is detached.
Plex failure
This is normally detected as a result of an uncorrectable I/O error.
The subdisk is detached.
RAID-5 subdisk
failure
When vxrelocd detects such a failure, it performs the following steps:
■ vxrelocd informs the system administrator (and other nominated users) by
electronic mail of the failure and which VxVM objects are affected.
See Partial disk failure mail messages.
See Complete disk failure mail messages.
See Modifying the behavior of hot-relocation.
■ vxrelocd next determines if any subdisks can be relocated. vxrelocd looks
for suitable space on disks that have been reserved as hot-relocation spares
(marked spare) in the disk group where the failure occurred. It then relocates
the subdisks to use this space.
■ If no spare disks are available or additional space is needed, vxrelocd uses
free space on disks in the same disk group, except those disks that have been
excluded for hot-relocation use (marked nohotuse). When vxrelocd has
relocated the subdisks, it reattaches each relocated subdisk to its plex.
■ Finally, vxrelocd initiates appropriate recovery procedures. For example,
recovery includes mirror resynchronization for mirrored volumes or data
recovery for RAID-5 volumes. It also notifies the system administrator of the
hot-relocation and recovery actions that have been taken.
If relocation is not possible, vxrelocd notifies the system administrator and takes
no further action.
Warning: Hot-relocation does not guarantee the same layout of data or the same
performance after relocation. An administrator should check whether any
configuration changes are required after hot-relocation occurs.
Relocation of failing subdisks is not possible in the following cases:
433Administering hot-relocation
How hot-relocation works