An EVA logical unit is referred to as a virtual disk (VDisk).
An EVA system can support up to 512 VDisks. VDisks are created within
a set of physical disk drives, referred to as a disk group. A VDisk
is striped across all the drives in the group.
The minimum size of a disk group is eight physical drives.
The maximum size of a disk group is all available disk drives.
EVA
VDisks are created and deleted using the Command View EVA utility.
Note: A
VDisk is formatted during the creation process; therefore, the capacity
of the VDisk will determine the length of time it takes to be created
and formatted. Ensure that you wait until the VDisk is created before
you present it to the SAN Volume Controller.
A single VDisk can consume the entire disk group
capacity or the disk group can be used for multiple VDisks. The amount
of disk group capacity consumed by a VDisk depends on the VDisk capacity
and the selected redundancy level. There are three redundancy levels:
- Vraid 1 - High redundancy (mirroring)
- Vraid 5 - Moderate redundancy (parity striping)
- Vraid 0 - No redundancy (striping)