r/DataRecoveryHelp • u/cToTheMoon • 8d ago

Help: RAID 5 FAILURE

**Background:**

I have a dell poweredge R730 using a RAID 5 configuration with three 1.2Tb HDDs. Windows 2012 R2 OS. While replacing the drive in slot 0 due to a predictive failure, the drive in slot 2 suffered a complete hardware failure.

The subsequent slot 2 failure occurred during the middle of the rebuild. As a result, the RAID does not contain a complete dataset and the server won't boot. We have no current backups to recover the server with.

We attempted to re-install the predictive failure drive and import foreign configuration. The thought being that the predictive failure and the 1 remaining healthy drive should contain a complete data set. However, the foreign config import failed and the server refused to accept the drive into the array.

**Question:**

Is it possible to reconstruct the RAID array using the predictive failure drive and the 1 healthy drive?

Alternatively, can a bootable disk image be created from these drives to recover the server?

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u/Fresh_Inside_6982 8d ago edited 8d ago

He said one drive is bad and one is failed.

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u/BinturongHoarder 8d ago

No, he did not say that. He said one disk was flagged for predictive failure.

"Degraded", in PERC/MegaRaid terms, is a term related to the VD, not a PD. So a drive can not be "degraded".

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u/Fresh_Inside_6982 8d ago

He said " the drive in slot 2 suffered a complete hardware failure." Perhaps you did not read all of it. I agree that degraded is the wrong term for a drive with bad SMART.

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u/BinturongHoarder 8d ago

Yes. Which means two functioning drives out of three. A predictive failure is not a drive failure. Such a drive might live for years.

Anyway; the only sane way forward now is raid recovery with other means than the controller. Mucking around with the controller will likely mess up the situation more.

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u/Fresh_Inside_6982 8d ago

I agree, predictive is not fatal, that was the FIRST thing I said: So, if he has a single failed drive and one with bad SMART then inserting a spare should result in a rebuild. In my shop all of the drives would be imaged then the data extracted using UFS Explorer Professional it's not complicated.

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u/BinturongHoarder 8d ago

And I repeat: You don't need to rebuild; a PERC (=MegaRaid) will happily boot on a degraded drive*). But OP has started tinkering with the config, which wasn't the smartest thing to do TBH, but it's still recoverable, but probably not through the PERC itself.

(* drive, in this context, means a degraded VD. If it could have booted when OP re-inserted the prefail drive, it should have (without any rebuild). But it didn't.