Hi there,

 

I've done some terrible and foolish things today, am hoping you can help. I made some changes to config across two disks and seem to have lost data in 1 (one disk is a new drive I added to replace an old one, and the other disk is a data drive that coincidentally errored and eventually I formatted it, mistakenly).

 

I hope people can take interest in the topic, in terms of - "can/how does unraid 's protection/dual parity etc help a silly person who takes the following path".

 

I have a dual parity system and am hoping that helps (before I look at things like UFS Explorer to recover data)...

 

In short, I wanted to swap a 4tb drive out for a larger 12tb drive, and in the process I mistakenly assigned the new 12tb drive to the wrong data drive slot when I restarted the array. All very silly, but I will swallow my pride and list the steps below in the hope someone can advise next steps.

 

Steps I took:

 

Added 12tb drive to unraid, precleared it.

Stopped array, changed 4tb drive slot (disk4) to 'no device', started array to update config.

Shutdown unraid, removed 4tb drive from machine, restarted.

(...disk3 coincidentally came up with red X and said drive missing)

I wasn't paying attention and I changed disk3 slot to the new 12tb drive, started the array.

I realised what I'd done and stopped the array.

I assigned the 12tb drive to disk 4, and set disk3 to the correct disk for its slot

Started array, parity rebuild started, disk 3 still red X.

I stopped the rebuild (perhaps I shouldn't have).

Disk3 could start a SMART report, so I took it to mean the drive was alive (didn't complete the report)

I went to New Config, chose to keep parity and keep cache settings (only data positions lost)

I'd taken a screenshot prior to messing with things, so I assigned all the data drives to original spots (incl original disk3 to disk3 slot, and the new 12tb drive to disk4)

Here is where I think I messed up.... I chose 'parity is valid'... 

 

When I started the array, it didn't start a rebuild and had disk3 as unformatted.

 

I thought... with dual parity, surely I can just format the disk3/4tb drive and have unraid rebuild the data across both disk3 and disk4... sure there's a risk if another drive fails, but I'll run with that.

 

I formatted disk3 to xfs.

 

I am now a bit panicked and not wanting to do anything else.

 

I've been looking for things like "how to roll back a New Config"... and now I looked up UFS Explorer as a last resort.

 

Can anyone advise next steps?

 

 

7 hours ago, BeeKay said:

When I started the array, it didn't start a rebuild

New config is not used to rebuild disks:

 

Also, parity can't help with a formatted disk, since it's updated in real time, and trying to rebuild a disk after a format will just rebuild the formatted disk, you'll need to try UFS explorer or a similar data recovery program.

 

 

1 hour ago, JorgeB said:

New config is not used to rebuild disks:

 

Also, parity can't help with a formatted disk, since it's updated in real time, and trying to rebuild a disk after a format will just rebuild the formatted disk, you'll need to try UFS explorer or a similar data recovery program.

 

 

Thanks JorgeB.

 

Understood, will look into the data recovery options.

 

I tke it there is no way to rollback to previous configs?

No, but you can just create one.

(For learnings sake) can you pinpoint which step I took that was the fatal blow?? and/or, where I should havetaken a different approach?

 

if i created the new config, but didn't tick the box saying parity was ok, would that have re-written the data to d3 and d4?

 

 

I know you've already said that new config isn't for rebuilding disks...

After replacing the wrong disk you either needed to let the rebuild finish or reassign both original disks, re-sync parity then start over.

thanks.

17 minutes ago, BeeKay said:

(For learnings sake) can you pinpoint which step I took that was the fatal blow?? and/or, where I should havetaken a different approach?

 

if i created the new config, but didn't tick the box saying parity was ok, would that have re-written the data to d3 and d4?

 

 

 

Since you had ticked the 'parity is already valid' box (thus laving parity intact) It might have also been possible to recover with some careful next steps if you had not formatted the drive (which also puts up a warning about this not being appropriate if you are attempting recovery) which then caused parity to be updated.