Recovering From Compromised Fault Tolerance; Replacing Hard Drives; Guidelines - HP Smart Array B140i User Manual

For example, fault tolerance may be compromised when a drive in an array fails while another drive in the
array is being rebuilt.
Compromised fault tolerance can also be caused by problems unrelated to drives. In such cases,
replacing the physical drives is not required.

Recovering from compromised fault tolerance

If fault tolerance is compromised, inserting replacement drives does not improve the condition of the
logical volume. Instead, if the screen displays unrecoverable error messages, perform the following
procedure to recover data:
Power down the entire system, and then power it back up. In some cases, a marginal drive will work
1.
again for long enough to enable you to make copies of important files. If a 1779 POST message is
displayed, do the following:
Press the F2 key and select Device Health Status.
a.
Select 1779 from the list of errors.
b.
Use the actions on the submenu to re-enable the logical volumes.
c.
Remember that data loss has probably occurred and any data on the logical volume is suspect.
Make copies of important data, if possible.
2.
Replace any failed drives.
3.
After you have replaced the failed drives, fault tolerance may again be compromised. If so, cycle the
4.
power again. If the 1779 POST message is displayed:
Press the F2 key and select 1779 from the list of errors. Then, use the actions on the submenu to
a.
re-enable the logical drives.
Recreate the partitions.
b.
Restore all data from backup.
c.
To minimize the risk of data loss that is caused by compromised fault tolerance, make frequent backups of
all logical volumes.

Replacing hard drives

If you are replacing a drive in a fault-tolerant configuration while the system is powered down, a POST
message appears when the system is powered up. When this message appears, press the F2 key and
select Device Health Status. Then, select the POST message and use the actions on the submenu to
enable automatic data recovery. If you do not enable automatic data recovery, the logical volume remains
in a ready-to-recover condition, and the same POST message appears when the system is restarted.
In RAID 1 configurations, you can replace one failed drive.
In RAID 1+0 configurations, drives are mirrored in pairs. If drives are not mirrored to removed or failed
drives, you can replace them simultaneously.
In RAID 5 configurations, you can replace one failed drive. When a physical drive fails, data that was on
the failed drive can be calculated from the remaining parity data and user data on the other drives in the
array. This recovered data is usually written to an online spare in a process called a rebuild.

Guidelines

Before replacing hard drives, observe the following guidelines:
•
Be sure that the array has a current, valid backup.
•
Confirm that the replacement drive is a SATA or SATA SSD drive
Replacing, moving, or adding hard drives 17