Raid 10 recovery on Dell Server – Perc 6/i

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I have a Raid 10 setup on Dell Perc 6/i controller with 4 drives + hot spare.

While server was off, new drive was added yesterday in drive 1 slot that was empty for last 2 months. After turning server back on, co-workers say Ctrl+R pages showed foreign config on all drives, they tried importing, didn't work, so they tried clearing, now pages show:

-VD Mgmt: Controller 0 – No Configuration Present!

-PD Mgmt:All drives show Ready State

Drives:

  • Drive 0 – 500Gb – (last of the originals) – Ready
  • Drive 1 – 1TB physical, limited by 500 gb drive – was pulled out 2 months ago when it died. Co-Worker placed new drive in this slot yesterday
  • Drive 2 – 1TB physical, limited by 500 gb drive – no issues
  • Drive 3 – 1TB – no issues
  • Drive 4 – 1TB – Hotspare, found dead today. I'm guessing it kicked in when drive 1 died or was pulled 2 months ago.

Is there any way to recover? I'm guessing that data will be lost if I create a new Virtual Disk Configuration…if anyone can confirm, that would be great. I'm not sure of the stripe size, guessing default.

Best Answer

Is there any way to recover?

If you happen to know the exact parameters used to originally create the Virtual Disk (especially the order of the disks and the strip-size) and if we assume that there are enough working disks - atleast 2 out of the 4 - which I understand to be the case from your description, you should be able to recreate the Virtual Disk configuration manually.

We still don't know, why it showed foreign config for all of the drives or why your coworkers weren't able to import the foreign-config. Maybe something with the controller is wrong, or it just got confused by the newly added drive (which shouldn't happen under normal circumstances), but as I understand you, that's more or less hearsay and you are unsure what was exactly done by your coworkers anyway.

I'm guessing that data will be lost if I create a new Virtual Disk Configuration

That's generally true. If you create a new Virtual Disk, the controller will initialize the VD as the last step of the wizard and destroy the existing data.

Fortunately the PERC6 offers to disable the initialization proccess, this is located in the Advanced Settings screen of the Create new VD wizard. For this use case (manually recreating a lost VD configuration) the users guide for the PERC6 therefor explicitely states:

CAUTION: Do not initialize virtual disks when attempting to recreate an existing configuration

Depending on the worth of the information on this volume you may of course also consider to ...

  • ... make a backup of all the disks before you proceed any further in case something goes badly wrong.
  • ... do as SmallLoanOf1M suggests and hire an expert data forensic company which is specialized in reassembling broken RAID arrays.
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