Configuring an Array
Compaq Smart Array 5i Plus Controller and Battery Backed Write Cache Enabler User Guide
7-25
COMPAQ CONFIDENTIAL
Writer: Amy L. Laffitte File Name: h-ch7 Configuring an Array
Codename: Executor Part Number: 266328-001 Last Saved On: 2/8/02 10:39 AM
6.
To save the logical drive settings, click
Controller
on the menu bar and select
Save Configuration
.
A progress bar in the lower right-hand corner of the screen shows the status of
the extension process.
7.
Make the extra capacity of the logical drive available to the operating system by
one of the following methods:
—
Create a new partition in the logical drive by using the operating system
partitioning software.
—
Increase the size of an existing partition by using the operating system
partitioning software or third-party partitioning tools.
Migrating RAID Level or Stripe Size
NOTE:
Before migrating the stripe size, check that the available memory on the array
accelerator is no smaller than the lowest common multiple of the total stripe sizes of the two
different configurations.
For example, consider the change from an 11-drive RAID 5 logical volume to a 14-drive
RAID 1+0 logical volume. If each configuration uses the corresponding default stripe width, the
block size changes from 16 kbytes per stripe to 128 kbytes per stripe.
•
A full stripe in the RAID 5 configuration contains 160 kbytes (ten of the drives contain user
data; one drive contains parity data).
•
A full stripe in the RAID 1+0 configuration contains 896 kbytes.
The lowest common multiple of the two stripe sizes is 4480 kbytes, and this figure represents
the minimum amount of memory that must be available on the array accelerator.
To migrate to a different RAID level or stripe size:
1.
Back up all data on the logical drive. Although migration is unlikely to cause
data loss, observing this precaution provides extra security. The backup data may
also be needed if the number of sectors needs to be increased (this fact will be
determined in step 8).
2.
Verify that the array accelerator batteries (if present) are fully charged.
NOTE:
The migration process takes about 15 minutes per gigabyte. A logical drive is
unavailable for any other process while it is undergoing migration, and no other logical
drive in the system can be expanded, extended, or migrated during this time.
