Recovering an HP Disk Array
As I reported earlier, my HP ML350 G5 died, and it was clearly a motherboard failure. Now that was bad enough, but worse was that I had VHD files on the P400 RAID5 array that were not as recently backed up as was desirable. Given that the ML350 wouldn’t boot at all, how to recover the important information on the array?
Well, thanks to a suggestion from Greg Starks, a friend at HP, I was able to completely and easily recover all the content of that array. The key requirement was to have a second machine that supported a similar HP RAID controller. And, by the way, it looks highly probable that the original RAID controller will be usable in a non-HP machine. But I digress.
I have an HP DL160SE G6 rack mount server here as well. Now it has a similar, though not identical, RAID controller built in to the motherboard. So, here’s what I did to get the files off the RAID array from the failed server:
- Built a USB pen drive with a bootable Windows Server 2008 R2 installation image on it. (The DL160SE doesn’t have an optical drive in it at all.)
- Removed each of the drives from the failed server, carefully marking each one with a piece of masking tape so I knew which slot they came out of.
- Removed each of the drives from the DL160, again marking the drives carefully with masking tape.
- Plugged the drives from the failed server in the exact same order and slot number. (These were all 2.5” SFF SAS drives, though the procedure is the same regardless.)
- Booted from the USB pen drive, and also plugged in a 1 TB external USB drive.
- Selected Recover at the initial boot screen for the Server 2008 R2 setup. This allowed me to get to a command prompt.
- At the command prompt, used
RoboCopy <sourcedrive> <targetUSBdrive> /mir
to copy the contents of the failed array onto the external USB drive. (Be patient, USB2 is slow.)
- Shutdown the HP160, and returned the original drives into their original slots. Removed all USB drives from the HP160 and booted normally.
Now, I had all the data files from the failed server on my 1TB USB disk, and I can put them anywhere.
What’s important to understand about this procedure is that it worked even though my array didn’t have any boot information on it. By making a boot USB stick, I could boot to that and suck off the files. And because the HP P400 RAID array drivers are built in to the Windows Server 2008 R2 installation image, the whole thing was completely painless and transparent.
The other thing I can’t stress enough. MARK EACH DRIVE as soon as you remove it from the array. All the information to use the array is on the drives, but if you screw up the disk order, no promises this will work, in fact it’s a good bet it will not.
I hope this helps someone else who is in the middle of a panic. A failed server is never fun, but this turned out to be a lot less pain than I initially feared.