Compaq Infortrend manual Different write policies within a logical volume?, Redundant Controller

Different write policies within a logical volume?

As members of a logical volume, all logical drives will be forced to adopt a consistent write policy. Whenever the write policy of a logical volume is changed, for example, the corresponding setting in its members will also be changed.

RAID expansion with logical volume?

The Logical Volume can also be expanded using the RAID expansion function. The concept of expanding a logical volume is similar to that of expanding a logical drive. To perform RAID expansion on a logical drive, replace each member physical drive with a drive of larger capacity or add a new drive, then perform logical drive expansion to utilize the newly-added capacity. For information about RAID expansion, please refer to Chapter 9 "Advanced Configurations."

To perform RAID expansion on a logical volume, expand each member logical drive, then perform “RAID Expansion” on the logical volume.

Steps to expand a Logical Volume:

1.Expand each member logical drive.

2.Expand the logical volume.

3.Map the newly-added capacity (in the form of a new partition) to a host LUN.

IMPORTANT!

•If a logical unit has already been partitioned, and you wish to expand its capacity, the added capacity will be appended to the last partition. You will not be able to proceed with expansion using firmware version earlier than 3.27 when the unit already has 8 partitions.

•Unless you move your data and merge two of the partitions, you will be not allowed to expand your logical volume. This is a precautionary limitation on logical unit expansion.

Different controller settings using logical volume?

Redundant Controller:

Without logical volume - logical drives can be assigned to the primary or the secondary controller. The host I/Os directed to a logical drive will be managed by the controller which owns the

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