Compaq Infortrend Note on Expansion, Added Capacity, Size of the New Drive, Applicable Arrays

from the original members to larger drives, and then the smaller drives can be replaced without powering down the system.

Note on Expansion

1. Added Capacity:

When a new drive is added to an existing logical drive, the capacity brought by the new drive appears as a new partition. Assuming that you have 4 physical drives (each of the size of 36GB) in a logical drive, and that each drive’s miximum capacity is used, you will have a logical drive of the size of 108GB. One drive’s capacity is used for parity; e.g., RAID 3. A 36GB drive is added, the capacity will be increased to 144GB in two separate partitions (one is 108GB and the other 36GB).

2.Size of the New Drive:

A drive used for adding the capacity should have the same capacity as that of the array’s members.

3.Applicable Arrays:

Expansion can only be performed on RAID 0, 3, and 5 logical drives. Expansion can not be performed on a logical configurations that do not have parity; e.g., NRAID or RAID 1.

NOTE:

•Expansion on RAID0 is not recommended, because the RAID0 array has no redundancy. Interruptions during the expansion process may cause unrecoverable data loss.

4.Interruption to the Process:

Expansion should not be canceled or interrupted once begun. A manual restart should be conducted after the occurrence of power failure or interruption of any kind.

12-2 Infortrend