Disabled Disk Questions w/Parity Upgrade

[dancue]

Hello, 

 

I have a disabled disk in my array and I had a few questions. 

• Once it is in disabled disk status, there is no saving the disk?
• How would I know if the disk can be used still? I can copy a log file here if that would help. Just need to point me to where I can get that.

 

Initially, when I saw disabled disk I thought I needed to prepare so I purchased a couple of drives. WD had a sale on 20TB drives so I grabbed two but no other drives in my array are that size, especially not the parity drives. 

 

The disk that is disabled is an older 6TB drive. The Parity drives are both 14TB. If I have to replace the 6TB disabled disk, my understanding is that I can't plug in a 20TB drive because they exceed the 14TB parity drives. So correct me if I'm wrong but should I do the following?

1. Replace both parity drives with the new 20TB drives
2. Use one of the ex-parity 14TB drives to replace the 6tb disabled disk.

 

If this is the case, what is the proper method step by step I should use. I can't just stop array move all disks where I want them and start array, can I? Do I have to replace each parity one at a time?

 

Any help with this would be great. Thanks!

[trurl]

Don't do anything without further advice.

 

Attach diagnostics to your NEXT post in this thread.

[dancue]

Here you go. That was quite simple.

mediarackserver-diagnostics-20220528-0949.zip

[trurl]

That disk should be replaced. Since you have so many disks I am not going to check the others, but you can.

 

First, since you have all WD disks, go to Disk Settings and add Custom Attributes 1 and 200 for monitoring. Then check if any of your other disks have SMART warnings on the Dashboard page.

 

Let us know what you find.

 

You can't do what you proposed since you can't replace 2 disks when you already have a disabled disk.

 

[dancue]

Like this?

 

Ok. Are you saying I should be checking the other disks before continuing? Is that absolutely necessary?

 

Can I replace the disk that is disabled now? Stop array, physically remove disk, enter new disk, start array? Then, when that is done can I replace the parity drives using the same method one at a time?

[trurl]

Now that you have turned on monitoring for those attributes, go to the Dashboard page and see if you have any SMART warnings for your disks. That is the simplest and quickest way to see all of them at once instead of clicking on each disk to examine their attributes.

 

The SMART indicator for each disk will be "thumbs up" and green, or "thumbs down" and orange.

 

Let us know which disks have warnings and I will take a closer look at them in the diagnostics you already posted.

[dancue]

If it happens right away, I only have one warning, (1) for disk 10. The disk that was disabled.

[trurl]

The purpose of all that was to make sure you don't have any other problems you don't know about that might cause problems during replacement / rebuild.

 

Do you Notifications setup to alert you immediately by email or other agent as soon as a problem is detected?

 

[dancue]

Yes. I use push notifications.

[dancue]

To be clear... pushover notifications on iOS. I get notified anything related to my server there.

[trurl]

Do you have backups of anything important and irreplaceable?

 

As you already noted, you can't replace a data disk with a disk larger than any parity disk. With dual parity, you can replace 2 disks at once, but since you already have a disabled disk, only that disabled disk and one other could be replaced at the same time.

 

There is a parity swap procedure that could allow both to be replaced then rebuild the data disk to one of the former parity disks but it is more complicated and it is probably safer to replace one at a time anyway even if everything were good.

 

Replace each parity disk, one at a time, and let parity rebuild.

 

Then replace the disabled disk with one of the former parity disks and let it rebuild.

 

 

[dancue]

oh. so I can do the parity upgrades before replacing the disabled disk? That's what I'll do then!

 

Thanks.

 

Also, for future reference... what did you look for in the logs to determine the disabled disk is no good. I'll probably use this thread as reference in the future. This will inevitably happen again at some point. First time it happened to me since getting on the Unraid train.

[dancue]

21 minutes ago, trurl said:

Do you have backups of anything important and irreplaceable?

 

 

 

Yes. Most of it is media that I can redownload. The few websites I have on it I have backed up already.

Edited May 28, 2022 by dancue
grammar

[itimpi]

2 hours ago, dancue said:

oh. so I can do the parity upgrades before replacing the disabled disk? That's what I'll do then!

You would be better off using the Parity Swap procedure to upgrade one parity disk to 20TB and using the existing 14TB disk to replace the failed drive.   You then have the other parity drive protecting you against a disk failure during this process.   When that completes you can consider upgrading the other parity drive to a 20TB drive.

[dancue]

Thank you. I will consider it. I feel like it would be better to do one at a time, though. I don’t mind the wait. 

[trurl]

2 hours ago, dancue said:

what did you look for

SMART report for the disk.

 

Click on the disk to get to its page and see the attributes, the problems will be hilited 

[dancue]

Right, but what problem told you the disk is not salvageable? Excuse me if that sounds ignorant. I’m genuinely asking.

[trurl]

33 minutes ago, itimpi said:

better off using the Parity Swap 

Ask if you have questions about the procedure. Note the array will be offline during parity copy 

[dancue]

3 minutes ago, trurl said:

Ask if you have questions about the procedure. Note the array will be offline during parity copy 

I’d prefer the array be on. Uptime is important for the websites. But I will ask if anything. Thank you

Edited May 28, 2022 by dancue

[trurl]

ID# ATTRIBUTE_NAME          FLAGS    VALUE WORST THRESH FAIL RAW_VALUE
  1 Raw_Read_Error_Rate     POSR-K   157   100   051    -    2280
  5 Reallocated_Sector_Ct   PO--CK   168   168   140    -    472
196 Reallocated_Event_Count -O--CK   001   001   000    -    205
197 Current_Pending_Sector  -O--CK   200   100   000    -    27
198 Offline_Uncorrectable   ----CK   200   100   000    -    27

Ideally RAW_VALUE for each of these would be zero. A small number in a few might be OK, but even then I wouldn't usually put back in the array since all bits of all disks are required to rebuild a missing disk, so it could put other disks at risk.

 

Pending sectors can become reallocated if the disk is forced to rewrite them, for example, but the disk already has a lot of reallocated sectors. All of these together are just too much.

[dancue]

Great. Thanks for taking the time to explain that.

[dancue]

Hoping someone can give me a quick answer here. I finally got the 20TB drives and when I plug it in it is in the unassigned devices area with the option to format. When I clicked on it it said I needed to enable destructive mode. Why?

 

Second... after enabling destructive mode I can format, but I don't know what format I should be using. I don't remember having the option to choose. What should I choose?

[JorgeB]

Didn't read the entire thread but you don't need to format a disk if it's going to be used to replace an array device.

[dancue]

 

1 minute ago, JorgeB said:

Didn't read the entire thread but you don't need to format a disk if it's going to be used to replace an array device.

ahh... it wasn't showing up on my list of devices to choose from in the drop down. It is now. Thanks for the quick response!!

[dancue]

Just wanted to add that it took 1 day, 18 hours to rebuild the first 20TB disk. Because my biggest size disk in the array was 14TB before, once it reached 14TB the speed of the rebuild almost doubled. Makes sense.

 

Now onto Parity Disk 2 and then the disabled disk.