Promise Technology EX8650 User Manual
Chapter 6: Technology Background
175
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).
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.
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.
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
larger logical drives
•
Quick – Overwrites the data bits on the first and last blocks of logical drive.
Takes only seconds.
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.
– 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.
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:
•
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.
Host PC.
•
Dedicated – An unassigned physical drive that can only be used by a
specified logical drive.
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.
failed drive is replace with a new drive. See “Transition” on page 185.
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.
be lost. Backup any important data before you initialize a logical
drive.