Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

42 Understanding Veritas Volume Manager
Volume layouts in VxVM
replaced, the entire plex must be brought up to date. Recovering the entire plex can take a
substantial amount of time. If a disk fails in a striped-mirror layout, only the failing
subdisk must be detached, and only that portion of the volume loses redundancy. When
the disk is replaced, only a portion of the volume needs to be recovered. Additionally, a
mirrored-stripe volume is more vulnerable to being put out of use altogether should a
second disk fail before the first failed disk has been replaced, either manually or by hot-
relocation.
Figure 1-19 How the failure of a single disk affects mirrored-stripe and striped-
mirror volumes
Compared to mirrored-stripe volumes, striped-mirror volumes are more tolerant of disk
failure, and recovery time is shorter.
If the layered volume concatenates instead of striping the underlying mirrored volumes,
the volume is termed a concatenated-mirror volume.
Striped plex
Striped-mirror
volume with
Striped plex
Detached
Mirrored-stripe
volume with
X
X
Failure of disk
detaches plex
Failure of disk removes
redundancy from a mirror
striped plex
no redundancy
partial
redundancy