RAID failure during OCE

alex_di

n00b
Joined
Mar 15, 2016
Messages
37
So, I did something dumb and want to review the recovery plan before I do something equally dumb.

I had this configuration:

Server 2019
Adaptec 71605
6x6TB in RAID-6

And I did this:

1. Updated the card's firmware
2. Installed the most recent version of MaxView listed for the drive (2014)
3. Did a fix/verify scrub of the array
4. Added 2 6TB drives for 8 in total
5. (here's the stupidity) Initiated an OCE to expand the RAID to 8x6TB and doubled the stripe size

It's been so long since I've done this, it didn't occur to me that the array would immediately transform into an 8-drive setup and be in a critical, degraded state during the OCE. (Or in essence that I was just simulating a two-drive failure on an 8-drive array.) I should have just expanded by a single drive at a time.

At 93% complete, a drive dropped with a SMART error. Then (I can't believe this) the logical device disappeared. I rebooted. The dropped drive is back, but all drives show Ready. There's no logical device.

Adaptec support suggested creating a new array *with the last optimal configuration* and skipping the Init step.

Does that make sense? I'm concerned that, with the OCE so far along with the new strip size, the 6-drive configuration won't be a close enough match. Maybe I've already lost the configuration portion of the drive so it doesn't matter if I choose wrong, but still-- any thoughts? Thanks.
 

mwroobel

[H]ardness Supreme
Joined
Jul 24, 2008
Messages
4,966
Before you do anything, you DO have a complete pre-expansion backup you can go back to, correct? In any case, before you do anything you should make image backups of all your existing array members, and only make your repair attempts on the copies until you have a working repair path. Unfortunately, I don't know the Adaptecs as well as I know the Arecas (Last I used the Adaptecs in any quantity was for SCSI.) That being said, what Adaptec support suggested is very similar to what you would do with an Areca with a similar failure. You just need to know the EXACT geometry of your array (block/stripe sizes, drive order, etc) before you begin.
 

alex_di

n00b
Joined
Mar 15, 2016
Messages
37
I have online backups of all the "important" data, but not of many media files. I do have the initial array configuration.

Update for anyone in a similar situation--

Adaptec insisted I use the original 6-drive scheme. The logical device creation failed, so I Uninitialized and Reinitialized each drive to clear any remnant of the RAID reconfiguration. Creating a 6-drive logical device was then successful.

My files didn't spontaneously reappear, but I did see the array in Disk Management in Windows. I Initialized the disk there (same GPT as before), but did not create a partition or map a drive latter. A quick check with a file recovery tool against the array suggests the files are still there, so I'm attempting to recover the partition. TBD if that works.
 
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