User's Manual

Virtual Disks 265
initialize can be completed quickly because existing information on the
physical disks is not erased, although future write operations overwrite any
information that remains on the physical disks.
NOTE: Doing a Fast Initialize causes existing data to be inaccessible. This task
should be considered data destructive.
In comparison with the Slow Initialize task, the Fast Initialize task has the
following advantages:
•The Fast Initialize task takes less time to complete.
•The
Fast Initialize task does not write zeroes to the disk blocks on the
physical disks. Because the
Fast Initialize task does not perform a write
operation, it causes less degradation to the disk than does the
Slow
Initialize
task.
If you have had trouble with a physical disk or suspect that it has bad disk
blocks, you may want to perform a Slow Initialize task, as this task remaps
bad blocks and writes zeroes to all disk blocks.
Considerations for Slow Initialize
Use the Slow Initialize task to initialize all physical disks included in the
virtual disk. The Slow Initialize task updates the metadata on the physical
disks and erases all existing data and file systems.
In comparison with the Fast Initialize task, you may want to use the Slow
Initialize task if you have had trouble with a physical disk or suspect that it
has bad disk blocks. The Slow Initialize task remaps bad blocks and writes
zeroes to all disk blocks.
The Slow Initialize task initializes one physical disk at a time. Each physical
disk displays the Clear state while being initialized. During the time that the
physical disk is in the Clear state, the Cancel Clear physical disk task is
available. Performing a Cancel Clear task on the physical disk causes the
Slow Initialize task to be cancelled for the entire virtual disk and all member
physical disks. For more information, see
Clear Physical Disk and Cancel
Clear
.