Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Planning a Workgroup
Setting Disk-Management Strategy
Chapter 282
Disk Mirroring
Disk mirroring is available only under LVM. See “Logical Volume
Manager (LVM)” on page 79.
Disk mirroring allows you to keep a live copy of any logical volume; the
data in that volume is in effect being continuously backed up. Strict
mirroring ensures that the mirror copy is on a separate disk (in the
same volume group).
Disk mirroring has the obvious advantages of increased data protection
and system availability, and the equally obvious disadvantage of
consuming twice as much disk space (or as many times more as there are
mirror copies). Use disk mirroring for volatile, mission-critical data; you
do not need to mirror volumes containing static software such as the
operating system.
Disk Striping
Disk striping is available only under LVM. See “Logical Volume Manager
(LVM)” on page 79.
Disk striping distributes logically contiguous data blocks (for example,
chunks of the same file) across multiple disks. This speeds I/O
throughput for large files when they are read and written sequentially
(but not necessarily when access is random).
The disadvantage of disk striping is that the loss of a single disk can
result in damage to many files, since files are purposely spread piecemeal
across two or more disks.
Consider using disk striping on file systems where large files are stored,
if those files are normally read and written sequentially and I/O
performance is important.