Dumb move - Deleted Partition; Format then rebuild?

[Aaron Oz]

I've done a few silly things around PC's in my life, this is right up there. Long story not told; I deleted the partition from one of my UnRaid drives while it was plugged into a PC. I just put the drive back into my UnRaid server without a partition.

 

I'm surprised that the array is started, without any warnings. It sees the correct drive in the correct spot, so I hope I've not confused UnRaid with this issue.

 

So-- I know I need to have UnRaid rebuild the drive, but what's the proper procedure for rebuilding the exact drive that was in there originally?

 

It currently says;

Unmountable disk present:
Disk 2 • ST31000524AS_6VPEE2RK (sdm)

 

I have a checkbox: Format will create a file system in all Unmountable disks, discarding all data currently on those disks.
 Yes I want to do this 

 

Do I let it format the drive, and then it will ask if I want to rebuild the array using the newly formatted drive?

 

[John_M]

14 minutes ago, Aaron Oz said:

Do I let it format the drive

NO!! That will destroy the data that you wish to restore.

 

Stop the array. Unassign the drive. Start the array. The emulated disk should mount. Stop the array. Reassign the drive. Start the array. The drive will be repartitioned and then rebuilt. I had a similar thing myself recently when the partition table was damaged by a failing HBA.

 

Edited November 21, 2018 by John_M
More info

[Aaron Oz]

Ah! So happy to have asked the question, then. Thanks!

Hearing you spell it out, that makes sense.

[trurl]

Format is never part of the rebuild process. Format writes an empty filesystem to the disk. Unraid treats this write operation exactly like any other, by updating parity.

 

Why did you have one of your array disks in another computer anyway? This is never advisable and if you had asked before doing it we might have been able to suggest another solution to whatever you were trying to accomplish.

[Aaron Oz]

Thanks, Trurl. Agreed, bad idea. I've never plugged an UnRaid drive into a WinPC before. And never planned to do it this time, either. So... some insight that might help anyone new to SAS drives; this is why it happened.

 

I have two SAS drives I just reformatted to 512b/sector. I added them to the drive housing for my server (it holds three drives per housing). One of the SATA drives from my UnRaid server was already in this housing. I wanted to do some testing and such to the SAS drives on my Windows machine. So I ran the housing with 3 drives over to my WinPC and plugged them in. Now, since SAS drives are a different connection than SATA, my two SAS drive connectors would only plug into the SAS drives, so there's no way I would accidentally plug my SATA UnRaid drive onto my SAS cable, right? Except I'm new to SAS drives, and just learned that the SAS connector is backwards compatible the SATA/Power connections.

So, without any need to think or checki/look, because there's no way I could have it hooked up wrong (as was my assumption), I deleted the partition on what I though were my two SAS drives. Except I deleted the partition to one SAS drive and from the existing UnRaid SATA drive.

 

Perfect example of not paying attention. Lesson learned.

Edited November 21, 2018 by Aaron Oz

[John_M]

Thanks for the explanation. I was curious but didn't like to ask. I admire your frankness so don't beat yourself up over it.

[Aaron Oz]

Yeah, thanks!

 

UnRaid is happily rebuilding the drive, now. Relatively inexpensive education, I suppose.