When you place a disk under VM control, a CDS disk layout is used, which ensures that the disk is accessible on different platforms, regardless of the platform on which the disk was initialized. By default in VxVM 4.0 and later, VM uses a cross-platform data sharing (CDS) disk layout.
A CDS disk consists of:
OS-reserved areas: The first 128K and the last two cylinders on a disk are reserved for disk labels, platform blocks, and platform-coexistence labels.
Private region: The private region stores information, such as disk headers, configuration copies, and kernel logs, and other platform-specific management areas that VxVM uses to manage virtual objects.
Public region: Represents the available space that VM can use to assign to volumes and is where an application stores data.
Comparing CDS and Sliced Disks
The sliced disk layout is still available in VxVM 4.0 and later, and is used for bringing the boot disk under VxVM control.
On platforms that support bringing the boot disk under VxVM control, CDS disks cannot be used for boot disks
