Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Chapter 7, Creating Volumes
Creating a Volume Using vxmake
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Note that because four subdisks are specified, but the number of columns is not specified,
the vxmake command assumes a four-column RAID-5 plex and places one subdisk in
each column. Striped plexes are created using the same method except that the layout is
specified as stripe. If the subdisks are to be created and added later, use the following
command to create the plex:
# vxmake -g mydg plex raidplex layout=raid5 ncolumn=4 stwidth=32
Note If no subdisks are specified, the ncolumn attribute must be specified. Subdisks can
be added to the plex later using the vxsd assoc command (see “Associating
Subdisks with Plexes” on page 178).
If each column in a RAID-5 plex is to be created from multiple subdisks which may span
several physical disks, you can specify to which column each subdisk should be added.
For example, to create a three-column RAID-5 plex using six subdisks, use the following
form of the vxmake command:
# vxmake -g mydg plex raidplex layout=raid5 stwidth=32 \
sd=mydg00-00:0,mydg01-00:1,mydg02-00:2,mydg03-00:0, \
mydg04-00:1,mydg05-00:2
This command stacks subdisks mydg00-00 and mydg03-00 consecutively in column 0,
subdisks mydg01-00 and mydg04-00 consecutively in column 1, and subdisks
mydg02-00 and mydg05-00 in column 2. Offsets can also be specified to create sparse
RAID-5 plexes, as for striped plexes.
Log plexes may be created as default concatenated plexes by not specifying a layout, for
example:
# vxmake -g mydg plex raidlog1 mydg06-00
# vxmake -g mydg plex raidlog2 mydg07-00
To create a RAID-5 volume, specify the usage type to be RAID-5 using the following
command:
# vxmake -g mydg -Uraid5 vol raidvol
RAID-5 plexes and RAID-5 log plexes are associated with the volume raidvol using the
following command:
# vxmake -g mydg -Uraid5 vol raidvol \
plex=raidplex,raidlog1,raidlog2
Note Each RAID-5 volume has one RAID-5 plex where the data and parity are stored.
Any other plexes associated with the volume are used as RAID-5 log plexes to log
information about data and parity being written to the volume.