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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.

webaholik
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  • Clearing the configuration from the drives really doesn't seem like a wise idea. Do you happen to know the parameters of the orginal RAID setup (stripe size, etc.)? Can you update your post with a timeline showing what happened (or supposedly) happened when? I'm not sure I can really follow your description. – s1lv3r Nov 25 '16 at 18:21
  • I'm not sure that it will be but, if it's any help and I recall correctly, we were in a similar situation (RAID-10 array, 4 physical drives, 1 physical drive failed, virtual drive disappeared) and we recovered by taking 1 healthy physical drive from each RAID-1 array, creating a new RAID-1 array, and imaging the data. – mythofechelon Nov 25 '16 at 19:22

1 Answers1

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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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s1lv3r
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  • As an additional note (and hopefully one you won't need), there are RAID reconstruction and recovery programs out there that you can use if none of this works for you. Also, there are recovery services that can do this for you, such as DriveSavers. They're expensive. – Spooler Nov 25 '16 at 18:52
  • @s1lv3r The second set should be fine, should I try rebuilding with or without new drive plugged into drive 1? – webaholik Nov 25 '16 at 18:54
  • @webaholik It shouldn't really make a difference, but I would personally prefer to have the setup as much identical to the time when the original configuration was created as possible, as this removes the room for some mistakes in the configuration process. So I would probably remove the newly added drive. – s1lv3r Nov 25 '16 at 19:01
  • @s1lv3r I agree, now to figure out how to do that...raid10 is only an option if I have 4 drives plugged in. Not sure how to proceed. Is it possible to bring back the good mirror in raid 1, then convert back to raid 10? What are the options? – webaholik Nov 25 '16 at 19:06
  • @webaholik I see you updated your question with the current disk status. I now understand and that really makes it a tiny bit more complicated. The PERC6 isn't able to create a VD with a missing drive from the start like mdadm let's you do. I think the suggested way to create a VD with a broken disk with a PERC6 is that you must create the VD with the new disk for Drive 1, but immediately after the VD creation (before you leave the controller BIOS!) set this disk to offline in the PD Mgmt (page 101 in the manual) so the controller doesn't use this (empty) drive to sync the array. – s1lv3r Nov 25 '16 at 19:37
  • @webaholik I tried to reassure the above information and found a guy who basically was in the same situation like you (only with RAID6): http://en.community.dell.com/support-forums/servers/f/906/t/19538386 Seems like this is really the way to go. – s1lv3r Nov 25 '16 at 19:42