Compromised fault tolerance, Recovering from compromised fault tolerance – HP Integrity rx4640 Server User Manual
Page 30

30
HP Smart Array P600 Controller for Integrity Servers User Guide
•
RAID 5 configurations can tolerate one drive failure.
•
RAID ADG configurations can tolerate simultaneous failure of two drives.
Compromised fault tolerance
If more hard drives fail than the fault-tolerance method allows, fault tolerance is
compromised, and the logical drive fails. In this case, all requests from the
operating system are rejected with unrecoverable errors. You are likely to lose
data, although it can sometimes be recovered (refer to "Recovering from
compromised fault tolerance" on page
One example of a situation in which compromised fault tolerance may occur is
when a drive in an array fails while another drive in the array is being rebuilt. If
the array has no online spare, any logical drives in this array that are configured
with RAID 5 fault tolerance will fail.
Compromised fault tolerance can also be caused by non-drive problems, such as
a faulty cable or temporary power loss to a storage system. In such cases, you do
not need to replace the physical drives. However, you may still have lost data,
especially if the system was busy at the time that the problem occurred.
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:
1.
Power down the entire system, and then power it back up. In some cases, a
marginal drive will work again for long enough to enable you to make copies
of important files.
If a 1779 POST message is displayed, press the F2 key to re-enable the
logical volumes. Remember that data loss has probably occurred and any
data on the logical volume is suspect.
2.
Make copies of important data, if possible.
3.
Replace any failed drives.
- Integrity rx7620 Server Integrity rx2600 Servers Integrity Superdome sx1000 Server Integrity rx7640 Server Integrity rx2620 Servers Integrity rx3600 Server Integrity Superdome sx2000 Server Integrity rx5670 Server Integrity rx8640 Server Integrity rx6600 Server Integrity BL860c Server-Blade Integrity rx2660 Servers Integrity rx8620 Server Integrity rx1620 Servers