MegaRAID - how do I reimport a lost VD+CacheCade array?

chrispitude

Member
Dec 14, 2017
38
1
8
46
Allentown, PA
Hi folks! I've got a 9260-8i with
  • 6 x 3TB drives in RAID5
  • a CacheCade SSD
  • a BBU unit
Last night around 2am, my wife and I were woken up by the shrieking alarm from my 9260-8i controller. I powered the machine off and went back to bed. (Sleeping kids + angry wife + exhaustion == not wanting to deal with it.)
This morning, I powered on the machine, entered WebBIOS, disabled the alarm. I found that I lost two 3TB drives (slots 4 and 5) and the CacheCade SSD (slot 6). All three of those drives were on an Ebay 3-way SATA power splitter special, which apparently decided to juuuust slightly unseat and lose its connection integrity overnight.

After fixing the power cabling and marking those three drives as Unconfigured(Good), this is what I have:

webbios.png

(The CacheCade array doesn't show in the logical view, perhaps because it has zero good drives now.)

So now I've got all seven drives back. But, I'm unable to figure out how to restore my configuration. I've got data in the controller cache and in the CacheCade drive. I don't see an import option offered anywhere. I was going to try clearing the configuration to look for it then, but I get a scary message that the controller cache will be discarded. All the data is sitting there - what's the right way to restore the configuration in this scenario?

I miss my 3ware where I plug it all back in and it works.

"For want of a decent SATA power splitter, a kingdom was lost." - me
 

poto

Active Member
May 18, 2013
198
60
28
Once you are sure drives that went offline are securely re-connected (data and power), you may import foreign configuration. IIRC, this is under "Configuration Wizard"

Rebuild or consistency check should initiate automatically. Best to limit I/O on array until complete.
 

chrispitude

Member
Dec 14, 2017
38
1
8
46
Allentown, PA
Once you are sure drives that went offline are securely re-connected (data and power), you may import foreign configuration. IIRC, this is under "Configuration Wizard"

Rebuild or consistency check should initiate automatically. Best to limit I/O on array until complete.
Hi poto,

I couldn't get to a point where I got to Import Configuration without hitting the scary cache message first, despite trying for awhile...

...but I did resolve the issue! First, here's the physical drive view I forgot to post earlier:

webbios2.png

All three drives are there. Then, I performed "Replace Missing PD" for each of the missing three drives to pull them back into the array, then "Make Online" for all three. In the process of doing this, the CacheCade array reappeared and correctly attached itself to the VD array; I did not have to take any action to resolve that.

Here is an article that describes exactly what to do, complete with YouTube walkthrough:

Monitoring Direct Attached Storage Under ESXi

I did get a warning about potential data corruption, which is to be expected when three drives depart the array for unknown-to-the-controller reasons - you've crossed the threshold of parity protection. Fortunately, the machine was idle when the drives lost power, and everything is back up and running without a hitch.