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| PC Server 500 - Drive maintenance
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| Service Hints &
Tips |
Drive
Maintenance
The
following section provides information about status indicators
for logical and hard disk drives, and the results of a hard
disk drive failure. It also contains procedures for replacing
defective drives and for redefining the space in an array by
replacing logical drives.
Obtaining Drive
Status
To see the
ID, capacity, and other information about each of the hard
disk drives attached to the RAID adapter:
1. Start the RAID
configuration program. See 'Starting the RAID Configuration
Program´.
2. Select Drive information.
3. Use the Up
Arrow (« ) key or the Down Arrow (» ) key to highlight each
of the drives shown in the Bay/Array selection list. As a
drive is highlighted, the information for that drive is shown
at the bottom of the screen.
4. Press Esc to return to the
Main Menu.
Note
The status of the hard disk
drive determines the status of the logical drives in the array
in which the hard disk is grouped.
Bay/Array
Selection List: The status of the drives in the Bay/Array
selection list is defined as follows:
| Status |
Meaning |
| CDR
|
CD-ROM
drive installed. |
| DDD |
Defective.
The drive is an online or hot-spare drive that does not
respond to commands. (If a RDY drive is defective or
powered down, it shows an empty bay (a blank status),
not a DDD status). |
| FMT |
Format. The
drive is being reformatted. |
| HSP |
Hot spare.
The drive will replace a similar drive that becomes
defective in real time. At that time, its status changes
to ONL, and its array association is
displayed. |
| OFL |
Offline.
The drive is a good drive that has replaced a defective
drive in a RAID level 1 or level 5 array. It is
associated with an array, but does not contain any valid
data. The drive state remains OFL during the rebuild
phase. |
| ONL |
Online. The
drive is part of an array. If this drive fails, logical
drives defined in the array in which this drive is
grouped will have a status of offline (if the logical
drive is assigned RAID level 0 with a good status) or
Critical (if the logical drive is assigned RAID level 1
or level 5 with a good status). |
| RDY |
Ready. The
drive is recognized by the adapter and is available for
definition. |
| TAP |
Tape drive
installed. |
| UFM |
Unformatted. The drive requires
a low-level format before it can be used in an
array. |
| Blank
Status |
Any of the
following circumstances can cause the status area to be
blank:
- No hard
disk drive is installed in that bay.
- The bay
contains a hard disk drive, but the drive is not
inserted correctly.
- An array was deleted and a
defective drive is still in the bay.
- A new drive was installed and
the configuration program has not been restarted. (The
status will change to RDY when the RAID configuration
program is
restarted.) |
Results of a Hard Disk
Drive Failure
Depending on the circumstances, there
can be several possible results from a drive
failure.
Example 1:
- Only one hard disk
drive fails.
- A hot-spare drive is defined that is the
same or greater size than the failed drive.
- The logical
drives in the array are assigned RAID level 1, level 5, or a
combination of these two levels.
Then the hot spare
will take over immediately.
Note
Data for
logical drives assigned RAID levels 1 and 5 is maintained;
however, system performance will be reduced. Hot-spare drive
capability does not apply to logical drives assigned RAID
level 0.
Example 2:
- Only one hard disk
drive fails. A hot-spare drive is not defined.
- The
logical drives in the array are assigned RAID levels 1, 5, or
a combination of these two levels.
Then no data will be
lost, but the system will operate at reduced performance until
the defective drive is replaced and rebuilt.
Example
3:
If more than one drive fails, all data is lost.
Therefore, it is important that you replace and rebuild a
defective drive as soon as possible.
Logical and Hard Disk
Drive Status Indications
The status of the hard disk drive
determines the status of the logical drives in the array in
which the hard disk is grouped.
- A single hard disk drive
failure (indicated by a DDD status in the Bay/Array selection
list) causes logical drives in that array that are assigned
levels 1 and 5 to have a Critical status. Data remains in
logical drives with a Critical status, but you must replace
the one defective hard disk drive promptly, because if two
hard disk drives were to fail, all of the data in the array
would be lost.
After you install a new hard disk
drive, the Replace process changes the drive status from DDD
to OFL if there is a Critical logical drive. After the Rebuild
process, the hard disk drive status changes from OFL to
ONL.
A single or multiple hard disk drive failure
causes logical drives in that array that are assigned level 0
to have an offline status. Data in logical drives with an
offline status is lost. However, with a multiple disk drive
failure, when the defective drives are part of the same array,
logical drives in that array will have an offline status. This
means that data is lost in all the logical drives in that
array, regardless of which RAID level is
assigned.
Replacing a Faulty Drive
Note
The hard disk drive
indicator light will blink when the drive has failed and needs
to be replaced (DDD state only).
To replace a faulty
drive:
1. Start
the RAID configuration program. See 'Starting the RAID
Configuration Program´. If the drive failed while the system
was powered down, a screen appears the next time the system is
powered on showing you which drive is defective.
2. If
the drive is not damaged (for example, it is not inserted
correctly):
a. Power-off the system.
b. Correct the
problem.
c. Remove the diskette.
d. Restart the
system.
3. If the drive is defective:
a. PressY
(Yes) to reconfigure the system.
b. Press Ctrl+ Alt+ Del
when instructed to restart the system. The Main Menu
appears.
c. Select Rebuild device.
At this point,
the drive status shows DDD.
Warning
Removing
the wrong hard disk drive can cause loss of all data in the
array.
d. Replace the defective drive. Refer to
'Removing a Drive from Bank C, D, or E´.
e. After you have
replaced the drive, press Enter. The system will reconfigure
to include the drive, and the drive's status will change to
OFL.
f. Allow the system to complete the configuration (the
screen displays a completion message); then select Rebuild
drive.
g. Use the Up Arrow (« ) key or the Down Arrow (»
) key to highlight the OFL (offline) drive you want to
rebuild; then press Enter.
The progress of the
rebuilding process appears on the screen.
h. When the
rebuilding process completes, press Esc to return to the Main
Menu. The new configuration will be saved automatically.
i.
Backup the new configuration (see 'Backing Up Your Disk-Array
Configuration´).
j. Select Exit to end the RAID
configuration program.
k. Remove the diskette and press
Ctrl+ Alt+ Del to restart the
system. |
| Document
ID: DDSE-3UVTUU |
| Last
Modified: 1999-01-22 |
| Copyright © 2000
IBM Corporation | | |
