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

Administering a System: Managing Disks and Files
Managing Disks
Chapter 6 591
two disks on each bus, the disks should be ordered so that disk 1 is on
bus 1, disk 2 is on bus 2, disk 3 is on bus 1, and disk 4 is on bus 2, as
depicted in Figure 6-4.
Figure 6-4 Interleaving Disks Among Buses
• Increasing the number of disks may not necessarily improve
performance. This is because the maximum efficiency that can be
achieved by combining disks in a striped logical volume is limited by
the maximum throughput of the file system itself and of the buses to
which the disks are attached.
Follow these steps to create a a striped logical volume:
1. Make the disks LVM disks using pvcreate.
2. Put the disks in a new or existing volume group using vgcreate or
vgextend.
3. Create the striped logical volume, defining its striping
characteristics using -i and -I options of lvcreate. The number of
stripes must be in the range 2 up to the maximum number of disks in
the volume group. The stripe size, the size of each of the blocks of
data that make up the stripe in kilobytes, must be one of the
following: 4, 8, 16, 32, or 64. If you plan to use the striped logical
volume for a JFS (VxFS) file system, then using a block size of 64KB
is recommended.