Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

■ Disks in the OTHER_DISKS category (disks that are not multi-pathed by DMP)
are named using the c#t#d# format or the disk## format.
By default, enclosure-based names are persistent, so they do not change after
reboot.
If a CVM cluster is symmetric, each node in the cluster accesses the same set of
disks. Enclosure-based names provide a consistent naming system so that the
device names are the same on each node.
To display the native OS device names of a VxVM disk (such as mydg01), use the
following command:
# vxdisk path | grep diskname
See “Renaming an enclosure” on page 189.
See “Disk categories” on page 85.
Private and public disk regions
Most VM disks consist of the following regions:
A small area where configuration information is stored, including a
disk header label, configuration records for VxVM objects, and an
intent log for the configuration database.
The default private region size is 32 megabytes (except for VxVM boot
disk groups where the private region size must be 1 megabyte), which
is large enough to record the details of several thousand VxVM objects
in a disk group.
Under most circumstances, the default private region size should be
sufficient. For administrative purposes, it is usually much simpler to
create more disk groups that contain fewer volumes, or to split large
disk groups into several smaller ones.
See “Splitting disk groups” on page 260.
If required, the value for the private region size may be overridden
when you add or replace a disk using the vxdiskadm command.
Each disk that has a private region holds an entire copy of the
configuration database for the disk group. The size of the configuration
database for a disk group is limited by the size of the smallest copy of
the configuration database on any of its member disks.
private region
An area that covers the remainder of the disk, and which is used for
the allocation of storage space to subdisks.
public region
81Administering disks
Disk devices