Problem with a HP NetRAID disk array

SemteX · October 9th, 2003, 11:15 AM

Hello.
I have a big ****** problem with my array at the HP NetServer LH4. I have (had) there an 4-disk level 5 array (each of the disks is 18.1 GB). As one of the disks failed I went into the BIOS to see which one of them failed. And I've accidentially deleted the configuration. Now I have some data on the disks, which I've not backuped. Do I have a chance to restore these data, or is it hopeless?
I need help, so if you have any ideas, could you please help me? (I've already tried to restore data with a program, but it didn't really helped, it was File Scavenger from QCC. Another problem is that I don't really know how the array was configured previously, but this is not a real problem I think.)

Profanity deleted
Fingers / TechIMO Moderator

Xaotic · October 9th, 2003, 12:32 PM

Please watch the language, per the rules.

If this controller's configuration is like most enterprise controllers, you should be able to go into the BIOS and read and apply the configuration stored on the hard drives(unless they've been overwritten). Hopefully, when you cleared the configuration, you did not save the configuration to the drives. If you did then it becomes a very expensive and not always successful procedure to attempt to restore the data. Good Luck!

SemteX · October 10th, 2003, 10:04 AM

Of course I didn't save the new configuration, but as I cleared the old, it seems that the controller has cleared the configuration on the disks too. That's my problem, I don't have any configuration.

Xaotic · October 10th, 2003, 12:02 PM

That's probably terminal. If you don't have the configuration on the hard drives and haven't backed up the configuration to a floppy, it's probably gone. There is one outside chance. Pull the other drives and reinstall the bad drive. It may spin up for long enough to read the configuration into the controller. It only takes one drive to do this.

SemteX · October 10th, 2003, 02:35 PM

Is there no other chance, on a program level or something? The data is on the disks, there must be a system how I can restore it. Or do I missunderstand something? I just can't believe that data which I actually have can't be restored.

Xaotic · October 10th, 2003, 04:50 PM

Unfortunately, I went through a similar process with about 350GB of preload images because someone unplugged the KVM and the data went away. The problem is that the configuration information is not available to be restored, perhaps it could be rebuilt. You could try calling Ontrack or other data restoration services, but it'll run into serious money very rapidly. I haven't tried to locate software for recovering RAID arrays, but it will not be freeware and likely to be very expensive with no guarantees. Due to these reasons, backup and redundancy strategy is one of the first things I think of when designing infrastructure.

SemteX · October 10th, 2003, 05:02 PM

What you are saying is right, but we aren't a big company, we just have 10 PCs and a half of them is really in use. And the server is the only server we have, all the files, documents and databases were there, but I've fortunately made a backup of the databases. And there are some important finance documents which I just need to restore.

Xaotic · October 10th, 2003, 09:22 PM

If someone was really good at hex data analysis, they might be able to extract sufficient information to reconstruct the array structure. Unfortunately, RAID-5 is great for normal usage, but when it fails 2 or more disks or loses configuration data, you're pretty much out of luck. I looked around for even payware software for rcovering RAID-5 and suspect that the only way to recover that data will be professional services. It might be worthwhile to call and get a quote(usually free) to establish whether it would be feasable to use the service.

SemteX · October 13th, 2003, 02:11 PM

What's the configuration data about, why is it a so crucial component? I just don't understand why is it so hard to restore it.

Xaotic · October 13th, 2003, 05:53 PM

The configuration data is stored on the disks and mirrors the RAID configuration stored in NVRAM on the array controller. It contains the information needed for the computer to initialize and read the array. This is stored in a manufacturer proprietary format and details among other things: stripe/cluster information, the number of drives, logical drive information, breakdown of any partition information, hot spare information, controller configuration and possibly BIOS and hardware revision information. This information is stored in either a hex or binary format and is necessary to restore the array. Misconfiguration will result in an unreadable array at best and destroyed data at worst. Unfortunately, it's not as simple as restoring a two drive RAID-0 stripe.