Veritas Volume Manager 5.0.1 Administrator's Guide, HP-UX 11i v3, First Edition, November 2009

RAID-5 log plexes for each RAID-5 volume protects against the loss of logging
information due to the failure of a single disk.
If you use ordered allocation when creating a RAID-5 volume on specified storage,
you must use the logdisk attribute to specify on which disks the RAID-5 log plexes
should be created. Use the following form of the vxassist command to specify
the disks from which space for the logs is to be allocated:
# vxassist [-b] [-g diskgroup] -o ordered make volume length \
layout=raid5 [ncol=number_columns] [nlog=number] \
[loglen=log_length] logdisk=disk[,disk,...] \
storage_attributes
For example, the following command creates a 3-column RAID-5 volume with the
default stripe unit size on disks mydg04, mydg05 and mydg06. It also creates two
RAID-5 logs on disks mydg07 and mydg08.
# vxassist -b -g mydg -o ordered make volraid 10g layout=raid5 \
ncol=3 nlog=2 logdisk=mydg07,mydg08 mydg04 mydg05 mydg06
The number of logs must equal the number of disks that is specified to logdisk.
See “Specifying ordered allocation of storage to volumes” on page 285.
See the vxassist(1M) manual page.
It is possible to add more logs to a RAID-5 volume at a later time.
See “Adding a RAID-5 log” on page 328.
Creating tagged volumes
Volume tags are used to implement the Dynamic Storage Tiering (DST) feature
of the Storage Foundation software.
See the Veritas File System Administrator’s Guide.
You can use the tag attribute with the vxassist make command to set a named
tag and optional tag value on a volume, for example:
# vxassist -b -g mydg make volmir 5g layout=mirror tag=mirvol=5g
To list the tags that are associated with a volume, use this command:
# vxassist [-g diskgroup] listtag volume
If you do not specify a volume name, the tags of all volumes and vsets in the disk
group are listed.
299Creating volumes
Creating tagged volumes