-3

I have a HP Proliant DL 380 G7 Server with a RAID 5 that has 2 failed disks.
My Question is, can i reduce the array to 3 hard disks that are remaining to work with them alone? Can I do this without loosing any data in the hard disks?

ewwhite
  • 201,205
Carey
  • 3

3 Answers3

7

No. RAID5 can only tolerate the loss of one disk (and occasionally, not even that many).

Your array is failed, and the data on it is gone.

So, the important thing here is that you learn from this mistake.

  1. RAID IS NOT A BACKUP! So take backups of all the data you care about.

  2. If your monitoring system had alerted you when the first drive failed, you'd probably have been able to replace the drive. A properly configured monitoring/alerting system is invaluable.

Community
  • 1
HopelessN00b
  • 54,273
1

That depends entirely on the type of array you have.

For an array of N disks, each type of RAID offers different levels of protection against the loss of one or more of those disks.

The currently in-use types of RAID are as follows:

RAID-1 (mirroring): N > 1; duplicates all data to all mirror disks. You can lose up to N-1 disks.

RAID-10 (striped mirroring): N > 3 and N is even; mirrors pairs of disks and stripes all mirrors into a larger array. You can lose one disk from each pair, up to N/2, but not both disks from a pair.

RAID-5 (striping with parity): N > 2; parity (error recovery) data is written for every N-1 stripes; you can lose up to 1 disk.

RAID-6 (striping with double parity): N > 3; parity data is written to two stripes for every N-2; you can lose up to 2 disks.

There are other, more obscure versions in use, such as RAID-1e and RAID-5e that don't follow such straight 1-to-1 assignments of stripes vs. drives, but it's unlikely you have one of those unless you already know the answer to your question.

adaptr
  • 16,746
1

If all else fails... try powering the system off, removing power for a few minutes and powering back on again.

These drives failed, but probably not at the same time. How long did you go before noticing or taking action? How do you know the drives have failed? Red LED light? Insight Manager report?

There are some odd firmware/controller combinations where disks report false failures. Your firmware probably isn't up-to-date, but if the server is still running, it's worth looking at updates.

ewwhite
  • 201,205