Promise Technology UltraTrak100 TX8 - Manual (Page 20)

UltraTrak100 TX4 and UltraTrak100 TX8
User Manual
14
A non-fault tolerant array goes "offline" when a drive is removed or fails. Since the
array is not fault tolerant, the data stored in the array is no longer accessible. If the
drive was removed, then it should be replaced to restore accessibility to the array.
If the drive failed, then the entire array must be deleted and re-initialized since all
data is considered lost.
R
EBUILDING
/S
YNCHRONIZING
F
AULT
T
OLERANT
A
RRAYS
Though a critical array can continue storage operations, it no longer offers fault
tolerance and should be addressed as soon as possible by replacing the missing
or failed drive(s).
Rebuild takes a replacement drive, assigns it to the array, and then writes the
redundancy data to it. Once the rebuild process is complete, the array status is
upgraded from “critical” to “functional” and fault tolerance is restored.
Synchronization is a preventative maintenance measure used to avoid problems
with data integrity. Synchronizing simply recalculates redundant data (similar to
the rebuild process) and matches the data on the drive(s).
To synchronize the array, go to the Configuration menu and select Configure
Array; then select Advance Features and choose Synchronize Array.
W
HEN A
D
ISK
D
RIVE
F
AILS
The UltraTrak100 provides both audible and visual indicators alerting you of a
drive failure. The following occur when a disk drive fails or goes offline:
•
Continuously produces short beeps every two seconds when a drive fails.
•
Continuously produces long beeps every 15 seconds when a drive is offline.
•
The Array LED on the front panel is yellow.
•
The disk drive Status LED (inside front panel door) is red.
•
The LCD displays a status message about the failure.
R
EPLACING A
D
ISK
D
RIVE
M
ODULE
UltraTrak100 disk drive modules should not be removed unless it has been
determined that a drive in the array has failed.
Generally, a disk drive that is a member of a fault tolerant array may be replaced
at any time without affecting the availability of data to the system. Depending on
the RAID type, drive removed, and type of access, performance may be reduced
until the drive is replaced.
Disk drives may be replaced while UltraTrak100 is running; special circuitry is
designed into the UltraTrak100 that protects the components and notifies the
processor.
Only a failed drive should be removed from the array. Removing any other drive
may cause the array to become unavailable. The replacement drive must be of
equal capacity or larger than the failed drive.
In arrays where a hot spare is already installed, the hot spare automatically
replaces the failed drive. When the failed drive is replaced, the new drive becomes
the new hot spare.