How should I recover my Cache drive contents?

[kennelfort]

TL;DR

I accidentally erased my SSD cache drive after I backed it up.

How should I recover the contents of the cache drive?

 

DETAILS

I was working on my server this weekend and made a stupid mistake. I'm really hoping the smart folks here can tell me the best way to fix this.

 

SYSTEM

Dell PowerEdge 520

UNRAID 6.7.2

16 GB RAM

8 HDDs

1 SSD Cache (120 GB)

No Parity Drives (still moving files over from old setup, so haven't turned on parity yet)

 

WHAT HAPPENED

A few days ago my server went offline (I run it headless).  I rebooted without even attaching a monitor.

After reboot it didn't come up so I attached a monitor, figured out it was a Kernel Panic caused by Flash OS corruption, and rebuilt the flash drive.

On reboot everything came back up fine. 

 

After fixing the corruption issue, I wanted to replace my 120 GB SSD cache with a new 1 TB SSD cache (to make copying large data sets easier).

Here is what I did next:

1. updated all dockers and plugins
2. made a backup using CA Backup / Restore Appdata
3. shut down the server
4. installed the new 1 TB SSD
5. forgot to plug in the SSD sata cable
6. booted the server
7. saw a cache drive listed that needed to be formatted
8. assumed it was the new drive
9. started the format
10. noticed that this was my original cache drive, NOT my new 1 TB SSD
11. YIKES!
12. Shut down
13. Attached the cable to the new SSD
14. Rebooted

Now the old cache drive now shows as unmountable, no UUID

 

Now I see this:

 

I really don't need the old SSD. I was planning on copying over everything from the old SSD to the new SSD. But now that I wiped the old cache drive, I'm not sure what the best recovery path is. I have the backup, but not sure if I should restore to the old SSD or the new one. Also not sure if the backup will have everything I need to restore the original cache files. Here is the CA BACKUP setup I had:

 

And here is what shows in the backup plugin under the Restore tab:

 

When I read this Restore page I went to the Shares tab and saw that all my shares were gone. I'm assuming they were part of the cache setup.

I'm still very new to UNRAID so I just stopped and created this post.

If you have any insight that can help me get things running again, I'd appreciate it.

Many thanks!

Edited November 19, 2019 by kennelfort

[testdasi]

Having all your shares "gone" is likely due to the USB stick corruption you had and not because of your formatting of the cache drive. This is assuming you have at least some shares with Cache = No (or Cache = Yes and you have already run the mover in the past).

 

Now, the reason you have "No Backup Sets Found" is probably because you set your data share to either Cache = Only or Cache = Yes so the backup was already erased by your formatting of the cache disk. (in the case of Cache = Yes, you might have formatted the cache before running the mover so the backup is still in cache).

 

So unfortunately I don't think your data is recoverable.

[kennelfort]

Hmmmm. 

So I did have some stuff hitting the cache. That was why I was planning to replace the cache. It was getting pegged all the time as I transferred lots of data or and I downloaded lots.

 

So the cache was definitely active, but when it crashed, I hadn't moved or downloaded anything in a day or so, certainly enough time for the Mover to have run (it's set to 1 hour).

 

Still, the mover would only have moved content and not the APPDATA folder. So APPDATA would not be recoverable without the backup data set, right?

 

I guess what I don't understand is that I watched the backup complete and it was set to back up to the a folder called BACKUP_APPDATA on a share called DATA. 

Shouldn't that still be there? I mean, assuming I can pull the HDDs and read them individually, I would expect to find that BACKUP_APPDATA folder on one or more HDDs with the files that make up the backup spread across them.

 

In other words, it's not breaking individual files into multiple parts across drives is it?

 

Edited November 20, 2019 by kennelfort

[JonathanM]

50 minutes ago, kennelfort said:

 

In other words, it's not breaking individual files into multiple parts across drives is it?

No, but if the data share was set to use the cache, it's possible the files hadn't been moved yet.

 

On the Main tab of the GUI, click on the yellow folder view at the far right beside each drive. There you can see what's on each drive.

[kennelfort]

Perfect.

Before we continue, allow me to say thanks for your help. I really appreciate it.

 

So here is what I see:

DRIVE 1

the other 2 backups are also here, but the one for BACKUP_USB is empty

 

and there is an empty APPDATA folder here:

 

DRIVE 2

No backup or appdata

 

DRIVE 3

No backup or appdata

 

DRIVE 4

No backup or appdata

 

DRIVE 5

No backup or appdata

 

DRIVES 6-8

Not mounted yet. Need to tape over the pins to get them to read.

 

So, what's the process for restoring from this backup? Or is there one?

 

 

 

 

 

 

Edited November 21, 2019 by kennelfort

[Squid]

Procedure is to hit the restore and then select the backup set.  If it's not finding a backup set, then there's something else presumably going on and it's probably due to the unmountable cache drive and you should post your diagnostics

[kennelfort]

Thanks. I can do that tonight.

 

Just to be clear, there's no problem hitting restore and pointing to the new Cache drive I put in? (assuming it can find the Restore Set)

[Squid]

A restore is the opposite settings of the Backup.  IE: You set the plugin up for how to backup, and don't change anything when you want to restore.  It'll figure it out.

[kennelfort]

Ok. Sorry to be so dense, but I'm trying to make sure I don't make any assumptions and mess this up even more.

I've got 2 SSDs now:

• The original SSD cache that I wiped and is now unmountable
• The new SSD - which hasn't yet been used as a cache drive - that is mounted and ready to use as cache. 

When you say "don't change anything when you want to restore", does that include the SSDs?

[Squid]

Yeah, as far as the Appdata Backup / Restore plugin is concerned, nothing changes.  If you're changing the SSD, then you do that, create your appdata share appropriately and run the restore

[kennelfort]

Cool. Last question for now. I've seen several mentions of creating my appdata share appropriately. What precisely is meant by that? Do I just create a folder called AppData and make it a share? Do I need to recreate the entire folder structure?

Edited November 22, 2019 by kennelfort