Promise Technology M300f, M500i, M500f, M300p, M500p, M300i, M200i, M200p, M200f manual Transition

VTrak M-Class Product Manual

A disk drive becomes unhealthy when:

•A SMART error is reported

•The bad sector remapping table fills to the specified level

Because data would be lost if written to a bad sector, when a bad sector is detected, the disk drive creates a map around it. These maps are saved in the bad sector remapping table, which has a capacity of 512 reassigned blocks and 1024 error blocks.

When the table fills to a specified percentage of its capacity, PDM triggers a migration of data from the suspect drive (the disk drive with the bad sectors) to a spare disk drive.

During data migration, you will have access to the Logical Drive but it will respond more slowly to read/write tasks because of the additional operation. The time required for data migration depends on the size of the disk drive.

See “Logical Drive PDM” on page 147.

Transition

The Transition feature enables you to specify “permanent” spare drives for your VTrak subsystem. Transition is the process of replacing a revertible spare drive that is currently part of a disk array with an unconfigured physical drive or a non- revertible spare. The revertible spare drive returns to its original status.

Transition happens automatically when the following sequence of events takes place:

•You create a revertible spare drive.

See page 151 (WebPAM PROe) or page 202 (CLU).

•A physical drive assigned to your disk array fails and the array goes critical or degraded.

•VTrak automatically rebuilds your array to the revertible spare drive and the array becomes functional again.

•You replace the failed physical drive with a new physical drive of equal or greater capacity.

•VTrak automatically transitions (moves) the data from the revertible spare to the new physical drive.

•The new physical drive becomes part of the array and the revertible spare drive returns to its original spare status.

Transition happens manually when you specify a different unconfigured physical drive to transition (move) the data from the revertible spare drive.

See the example below.

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