218Creating and administering subdisks

Joining subdisks

For example, to split subdisk mydg03-02, with size 2000 megabytes into subdisks mydg03-02, mydg03-03, mydg03-04and mydg03-05, each with size

500 megabytes, all in the disk group, mydg, use the following commands:#vxsd -g mydg -s 1000m split mydg03-02 mydg03-02 mydg03-04#vxsd -g mydg -s 500m split mydg03-02 mydg03-02 mydg03-03#vxsd -g mydg -s 500m split mydg03-04 mydg03-04 mydg03-05

Joining subdisks

Joining subdisks combines two or more existing subdisks into one subdisk. To join subdisks, the subdisks must be contiguous on the same disk. If the selected subdisks are associated, they must be associated with the same plex, and be contiguous in that plex. To join several subdisks, use the following command:

#vxsd [-gdiskgroup] join subdisk1 subdisk2 ... new_subdisk

For example, to join the contiguous subdisks mydg03-02, mydg03-03, mydg03- 04 and mydg03-05as subdisk mydg03-02in the disk group, mydg, use the following command:

#vxsd -g mydg join mydg03-02 mydg03-03 mydg03-04 mydg03-05 \ mydg03-02

Associating subdisks with plexes

Associating a subdisk with a plex places the amount of disk space defined by the subdisk at a specific offset within the plex. The entire area that the subdisk fills must not be occupied by any portion of another subdisk. There are several ways that subdisks can be associated with plexes, depending on the overall state of the configuration.

If you have already created all the subdisks needed for a particular plex, to associate subdisks at plex creation, use the following command:

#vxmake [-g diskgroup] plex plex sd=subdisk,...

For example, to create the plex home-1and associate subdisks mydg02-01, mydg02-00, and mydg02-02with plex home-1, all in the disk group, mydg, use the following command:

#vxmake -g mydg plex home-1 sd=mydg02-01,mydg02-00,mydg02-02

Subdisks are associated in order starting at offset 0. If you use this type of command, you do not have to specify the multiple commands needed to create the plex and then associate each of the subdisks with that plex. In this example, the subdisks are associated to the plex in the order they are listed (after sd=). The disk space defined as mydg02-01is first, mydg02-00is second, and mydg02-02is third. This method of associating subdisks is convenient during initial configuration.