Two Failed Drives out of 5 - How to restart my array...

[kc4uai]

Ok, Right from the start, I'll admit that I'm stupid, but it was late, I was tired and I didn't understand what was happening.  This all started because I had a new larger drive to install, and being the largest I was going to put it in the parity slot.  Nice plan.

 

To make a long story short, I had two drives fail (Parity and disk 1) due to both cabling issues and a stupid mistake. I managed to backup the data on the bad drive to another drive not in the array.  I currently have two drives precleared and ready to go back into the array but I'd like to preserve the data on the three drives remaining.

 

How can I do this?  I'm guessing it's through tools -> New Config but the warning on that page has me concerned.   Can you add drives with data back to an array and not lose the data when you do if I start a new config?  If so, how?

 

Thanks for helping me out.

[JonathanM]

The only drives that will be immediately altered when using new config are the parity slots. If you want to be absolutely sure things are going how you want, just do the new config with only data drives. You can always add parity drives later.

[6of6]

4 hours ago, kc4uai said:

How can I do this? 

Calm down and take your time. The world will be the same tomorrow. I know that sounds stupid and tree-hugger, but it actually is/will.

 

Under these circumstance, I might have my daughter screaming that her movies aren't working, and my son freaking about his games!!!

 

My best advise is don't format anything until tomorrow. You'll wake up tomorrow and feel so much better about today. That stupid "logic" has saved me so many times.

 

We think best when we first awake (<-- that's copyright by me if no one said it first... LMAO 🤑).

 

6.

 

[JonathanM]

And whatever you do, DON'T FORMAT anything. If a disk that should have data shows unmountable, you need to fix the filesystem, NOT FORMAT.

[kc4uai]

10 hours ago, jonathanm said:

And whatever you do, DON'T FORMAT anything. If a disk that should have data shows unmountable, you need to fix the filesystem, NOT FORMAT.

 

Unfortunately, I already formatted it. Yes, I admit, it was a stupid thing to do, and I usually know better.  This was a multiple drive failure due to a cabling issue I induced when inserting a new drive.  I was able to copy the data off the drive BEFORE I erased it, so I've not lost anything yet, except a bunch of time.

 

Right now, I'm waiting for the parity to finish rebuilding.  I've got the data drive precleared waiting in the wings and I'll add it back into the array.  Once it's formatted and everything is in sync, I'll copy the data from the backup to the old drive.  Then I'll be back where I started.

[kc4uai]

23 hours ago, jonathanm said:

The only drives that will be immediately altered when using new config are the parity slots. If you want to be absolutely sure things are going how you want, just do the new config with only data drives. You can always add parity drives later.

 

My concern was that a "new config" would force drives to be reformatted when I added them back into the array.  However, it's not required to reformat a drive to put it into the array.  I know that now..

 

So I'm in the process of rebuilding parity for the array which consists of the untouched data drives.  Once this is done, I have the drive that failed due to wiring issues passing both the Smart checks and a full preclear waiting in the wings.  I'll add this as a blank drive into the array, copy the data from my backup back into place and be back where this all started.

 

Thanks!

[JonathanM]

21 minutes ago, kc4uai said:

However, it's not required to reformat a drive to put it into the array. 

That's a misleading statement. and only applies to a new config with drives with a partition layout and format compatible with Unraid parity array drives.

 

Once parity is established, any drive added will be filled with zeroes to keep parity valid as the drive is added. If you want to add a compatible drive and leave the data intact you must do a new config and build fresh parity.