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

Administering a System: Managing Disks and Files
Managing Disks
Chapter 6 593
• If you plan to use the striped logical volume for a JFS (VxFS) file
system:
Use the largest available size, 64KB. For I/O purposes, JFS combines
blocks into extents, which are variable in size and may be very
large. The configured block size, 1KB by default (which in any case
governs only direct blocks), is not significant in this context. See
“Frequently Asked Questions about the Journaled File System” on
page 87 for more information.
• If you plan to use the striped logical volume as swap space:
Set the stripe size to 16KB for best performance. See “Setting Up
Logical Volumes for Swap” on page 565 and “Configuring Primary
and Secondary Swap” on page 670 for information on configuring
swap.
• If you plan to use the striped logical volume as a raw data partition
(for example, for a database application that uses the device
directly):
The stripe size should be the same as the primary I/O size for the
application.
You may need to experiment to determine the optimum stripe size for
your particular situation. To change the stripe size, you will need to
re-create the logical volume.
LVM Procedures
NOTE All of these procedures require you to be the root user on the system you
are modifying.
• Quick Procedure for “Adding a Disk” on page 861
• “Adding a Logical Volume” on page 862
• “Adding a Logical Volume with Mirroring” on page 863
• “Extending a Logical Volume” on page 864
• “Extending a Logical Volume When You Can’t Use SAM” on page 866
• “Reducing a Logical Volume” on page 868