Promise Technology EX8650A, EX4650A user manual Initialization, Hot Spare Drives

Chapter 6: Technology Background

Without Capacity Coercion, the controller will not permit the use of a replacement physical drive that is slightly smaller than the remaining working drive(s).

Initialization

Initialization is highly recommended for logical drives when they are created from a disk array. Initialization sets all data bits in the logical drive to zero. The action is useful because there may be residual data on the logical drives left behind from earlier configurations. You can also perform an Initialization on an existing logical drive.

Warning

When you initialize a logical drive, all the data the logical drive will be lost. Backup any important data before you initialize a logical drive.

There are three options for logical drive initialization:

•Full – Overwrites all data bits on the logical drive. Can take some time for larger logical drives

•Quick – Overwrites the data bits on the first and last blocks of logical drive. Takes only seconds.

•None – Leaves residual data on the logical drives. Not recommended.

See “Creating a Logical Drive” on page 65 and page 136, “Creating a Disk Array

–Advanced Configuration” on page 132, and “Initializing a Logical Drive” on page 146.

Hot Spare Drive(s)

A hot spare is a physical drive that is connected to the logical drive system but is not assigned as a member of the logical drive. In the event of the failure of a drive within a functioning fault tolerant logical drive, the hot spare is activated as a member of the logical drive to replace the failed drive.

SuperTrak will replace a failed physical drive in a logical drive with a hot spare drive, if one is available. There are two types of hot spare drive:

•Global – An unassigned physical drive available to any logical drive on the Host PC.

•Dedicated – An unassigned physical drive that can only be used by a specified logical drive.

There is another property you can assign to a hot spare drive:

•Revertible – A revertible spare drive will return to spare status when the failed drive is replace with a new drive. See “Transition” on page 185.

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