Veritas Storage Foundation Portable Data Containers: Cross-Platform Data Sharing 5.0.1 Administrators Guide, HP-UX 11i v3, First Edition, November 2009

See “Converting non-CDS disks to CDS disks” on page 24.

All VxVM objects in a CDS disk group are aligned and sized so that any system

can access the object using its own representation of an I/O block. The CDS disk

group uses a platform-independent alignment value to support system block sizes

of up to 8K.

See “Disk group alignment” on page 17.

CDS disk groups can be used in the following ways:

■ Initialized on one system and then used “as-is” by VxVM on a system employing

a different type of platform.

■ Imported (in a serial fashion) by Linux, Solaris, AIX, and HP-UX systems.

■ Imported as private disk groups, or shared disk groups (by CVM).

You cannot include the following disks or volumes in a CDS disk group:

■ Volumes of usage type root and swap. You cannot use CDS to share boot devices.

■ Encapsulated disks.

Note: On Solaris and Linux systems, the process of disk encapsulation places the

slices or partitions on a disk (which may contain data or file systems) under VxVM

control. On AIX and HP-UX systems, LVM volumes may similarly be converted to

VxVM volumes.

Device quotas

Device quotas limit the number of objects in the disk group which create associated

device nodes in the file system. Device quotas are useful for disk groups which to

be transferred between Linux with a pre-2.6 kernel and other supported platforms.

Prior to the 2.6 kernel, Linux supported only 256 minor devices per major device.

You can limit the number of devices that can be created in a given CDS disk group

by setting the device quota.

See “Setting the maximum number of devices for CDS disk groups” on page 37.

When you create a device, an error is returned if the number of devices would

exceed the device quota. You then either need to increase the quota, or remove

some objects using device numbers, before the device can be created.

See “Displaying the maximum number of devices in a CDS disk group” on page 41.

Note: The default device quota for HP-UX is 32767.

Overview of CDS

CDS disk access and format