SmartStor NAS User Manual
− PDM:
Predictive Data Migration (PDM) is the migration of data
from the suspect disk drive to a spare disk drive, similar to
rebuilding a logical drive. But unlike
Rebuilding, PDM
constantly monitors your disk drives and automatically
copies your data to a spare disk drive BEFORE the disk
drive fails and your logical drive goes Critical.
The following actions trigger PDM:
A disk drive with unhealthy status (see below)
Media Patrol finds a disk critical error
You initiate PDM manually
PDM also counts the number of media errors reported by
Media Patrol.
A disk drive becomes unhealthy when:
A SMART error is reported
The bad sector remapping table fills to the specified
level.
You can specify the maximum levels for the reassigned and
error blocks in PDM settings. When the table fills to a
specified value, PDM triggers a migration of data from the
suspect drive (the disk drive with the bad sectors) to a
replacement physical drive.
During data migration, you will have access to your logical
drives but they 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 drives.
PDM is enabled on all disk arrays by default. You can
disable PDM in the disk array settings, however that action
is not recommended.
54
To Next Page
Loading...
Need help?
General
