Veritas Storage Foundation 5.1 SP1 Advanced Features Administrator"s Guide (5900-1503, April 2011)

configuration database. The default private region size is 32MB, which is large
enough to record the details of several thousand VxVM objects in a disk group.
The public region covers the remainder of the disk, and is used for the allocation
of storage space to subdisks.
The private and public regions are aligned and sized in multiples of 8K to permit
the operation of CDS. The alignment of VxVM objects within the public region is
controlled by the disk group alignment attribute. The value of the disk group
alignment attribute must also be 8k to permit the operation of CDS.
Note: With other (non-CDS) VxVM disk formats, the private and public regions
are aligned to the platform-specific OS block size.
Disk access type auto
The disk access (DA) disk type auto supports multiple disk formats, including
cdsdisk, which is supported across all platforms. It is associated with the DA
records created by the VxVM auto-configuration mode. Disk type auto
automatically determines which format is on the disk.
Platform block
The platform block resides on disk sector 0, and contains data specific to the
operating system for the platforms. It is necessary for proper interaction with
each of those platforms. The platform block allows a disk to perform as if it was
initialized by each of the specific platforms.
AIX coexistence label
The AIX coexistence label resides on the disk, and identifies the disk to the AIX
logical volume manager (LVM) as being controlled by VxVM.
HP-UX coexistence label
The HP-UX coexistence label resides on the disk, and identifies the disk to the HP
logical volume manager (LVM) as being controlled by VxVM.
VxVM ID block
The VxVM ID block resides on the disk, and indicates the disk is under VxVM
control. It provides dynamic VxVM private region location and other information.
CDS disk groups
A CDS disk group allows cross-platform data sharing of VxVM objects, so that
data written on one of the supported platforms may be accessed on any other
459Migrating data between platforms
CDS disk format and disk groups