Creating a volume using vxmake

As an alternative to using vxassist, you can create a volume using the vxmake command to arrange existing subdisks into plexes, and then to form these plexes into a volume.

The example given in this section is to create a RAID-5 volume using vxmake.

Creating a RAID-5 plex for a RAID-5 volume is similar to creating striped plexes, except that the layout attribute is set to raid5. Subdisks can be implicitly associated in the same way as with striped plexes. For example, to create a four-column RAID-5 plex with a stripe unit size of 32 sectors, use the following command:

# vxmake -g mydg plex raidplex layout=raid5 stwidth=32 \
  sd=mydg00-01,mydg01-00,mydg02-00,mydg03-00

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

If no subdisks are specified, the ncolumn attribute must be specified. Subdisks can be added to the plex later using the vxsd assoc command.

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 sd=mydg06-00
  # vxmake -g mydg plex raidlog2 sd=mydg07-00

The following command creates a RAID-5 volume, and associates the prepared RAID-5 plex and RAID-5 log plexes with it:

# vxmake -g mydg -Uraid5 vol raidvol \ 
  plex=raidplex,raidlog1,raidlog2

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.

After creating a volume using vxmake, you must initialize it before it can be used.

More Information

Creating subdisks

Associating subdisks with plexes

Initializing and starting a volume