RAID 5 Recovery - what happens?

[Rison]

Hey guys, a bit of a novice debate here.

Let's take a hardware Raid card (for instance, LSI 4 port PCIe)

Build a raid 5 array. Put a bunch of data on it. The raid card fails.

What is the recovery option? My boss assumes you can put another raid card of the exact same model, and the raid would come back, no data loss. I told him that's not how it works, and that is why there are BBUs to keep the raid config on the card. If you put the similar card in, it would see three empty drives.

My google skills are failing me with the little sleep I have had, and didn't find a direct resource with this answer.

Thanks in advance.

[Keywork]

I don't know the answer but there are a few people over at the NCIX forums who could answer this lickety-split.

[enaberif]

It shouldn't cause any problems whatsoever.

You can do the same thing with a RAID setup on a Intel ICHR chipset.

[Nexitus]

Typically, if you replace it with the same card, it should be able to see the RAID that was built by the previous card given that there is no RAID corruption done.

[Rison]

Yeah, I see that now, I was unaware that if you had an exact same card - that it could rebuild the array from the metadata on the hard drives. We're testing it tomorrow anyways to be certain.

My boss also thinks that a synology disk station that hosts a users data is a "backup" - I'm trying slowly to tell / teach him that it's not a backup.. because it's the only storage. I dunno if the synology disk station board dies, we're hooped. We need a more stable offsite backup plan for our customers anyways - some are just too cheap though. Anywho.

[MARSTG]

yeah, better have one spare card the same model as backup. there are also online solutions for backing up data or store it online. more like backup in this case.

[Squeetard]

Most Raid controllers store all the metadata on the array itself. Some store it on onboard cache. Those are usually enterprise class solutions that have redundant cards though.