VERITAS Volume Manager 4.1 Administrator's Guide

Understanding VERITAS Volume Manager
Online Relayout
Chapter 142
• Change the column stripe width in a volume. See Figure 1-31,
“Example of Increasing the Stripe Width for the Columns in a
Volume,” below.
Figure 1-31 Example of Increasing the Stripe Width for the Columns in a
Volume
For details of how to perform online relayout operations, see “Performing
Online Relayout” on page 318.
Limitations of Online Relayout
Note the following limitations of online relayout:
• Log plexes cannot be transformed.
• Volume snapshots cannot be taken when there is an online relayout
operation running on the volume.
• Online relayout cannot create a non-layered mirrored volume in a
single step. It always creates a layered mirrored volume even if you
specify a non-layered mirrored layout, such as mirror-stripe or
mirror-concat. Use the vxassistconvert command to turn the layered
mirrored volume that results from a relayout into a non-layered
volume. See “Converting Between Layered and Non-Layered
Volumes” on page 322.
• Online relayout can be used only with volumes that have been
created using the vxassist command or the VERITAS Enterprise
Administrator (VEA).
• The usual restrictions apply for the minimum number of physical
disks that are required to create the destination layout. For example,
mirrored volumes require at least as many disks as mirrors, striped
and RAID-5 volumes require at least as many disks as columns, and
striped-mirror volumes require at least as many disks as columns
multiplied by mirrors.
• To be eligible for layout transformation, the plexes in a mirrored
volume must have identical stripe widths and numbers of columns.
Relayout is not possible unless you make the layouts of the
individual plexes identical.