Added new drives, assigned data drive as parity


isaw

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Hi.   I'm stupid.

 

I was installing additional 8TB drives and removing 2 empty drives at the sometime to my unriad server and when I hit new config.  I did press keep drive assignments but when trying to start the array I had 1 drive too many connected.     Upon rebooting I lost the assignments.

 

I tried to assign the correct drives but I didnt get it right, and i allowed one of my data drives to become the parity drive for about 2 minutes.  So now I need some help.....

 

 

1.   How can i figure out what drive is the correct parity drive?

2. How can I recover the data they should be on the data drive?

 

I'm hoping once i know what drive should go where I might stand a fighting chance of not losing much....

any advice and help would be greatly appreciated right now

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When you don't know which drive is parity you should assign no parity drives and assign all as data. The parity drive will be unmountable since it has no filesystem.

 

In your case you will have another unmountable drive, the one you wrongly assigned as parity.

 

You will have to do invalidslot to have any chance of rebuilding the data disk.

 

Go to Tools - Diagnostics and attach the complete diagnostics zip file to your NEXT post.

 

Then don't do anything else and wait for further advice. Since it is late for some of us you may be waiting a few hours to get that further advice.

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Reading though https://wiki.unraid.net/Check_Disk_Filesystems#Drives_formatted_with_XFS   I know the drive was formatted with XFS,  but I allowed it to be overwritten and become a parity drive (for a very short time!).     If I force a repair for XFS on both the parity and the data drive will that matter?

 

I'm still not sure what drive was data and what was parity.   SDD or SDB.     SDC is correct as data.

dozer-diagnostics-20200215-1521.zip

Edited by isaw
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4 minutes ago, isaw said:

Reading though https://wiki.unraid.net/Check_Disk_Filesystems#Drives_formatted_with_XFS   I know the drive was formatted with XFS,  but I allowed it to be overwritten and become a parity drive (for a very short time!).     If I force a repair for XFS on both the parity and the data drive will that matter?

 

I'm still not sure what drive was data and what was parity.   SDD or SDB.     SDC is correct as data.

See my reply and don't do anything except get us the diagnostics.

 

And forget about drive letters. Drive letters are not guaranteed to be consistent from one boot to another, especially if you add, remove, or change disks connections. Unraid identifies drive assignments using the disk serial numbers. The serial numbers are the only thing you should pay attention to except when advised otherwise.

 

 

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6 hours ago, isaw said:

I was installing additional 8TB drives and removing 2 empty drives

4 hours ago, johnnie.black said:

were the new drives you were adding already cleared? If not they can't be used with parity right away.

Sounds like parity would need the 2 empty drives also. And I assume it would be best if we could figure out which disk was parity without having to mount them all as data.

 

@isaw

 

Do you have any screenshots, diagnostics, or syslogs from before?

 

Do you have backups of anything important and irreplaceable?

 

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4 hours ago, johnnie.black said:

also and before starting were the new drives you were adding already cleared? If not they can't be used with parity right away.

 

 

no,  the new drives were not cleared so they show up as unmountable currently and need formatting.  they have not been created as part of the array.

the 2 other drives that were in the system before being pulled out are still on my desk (1tb's)  but there was nothing on them.

 

1 minute ago, trurl said:

Sounds like parity would need the 2 empty drives also. And I assume it would be best if we could figure out which disk was parity without having to mount them all as data.

 

@isaw

 

Do you have any screenshots, diagnostics, or syslogs from before?

Do you have backups of anything important and irreplaceable?

 

I have the 2 empty drives, and can reinstall them into the system if need be.

Ideally I want to identify the drive with the data, and the one with the parity first.  following that I'd like to retry to correct the file system back to xfs,   and maybe then try to rebuild from the parity.

 

@trurl thanks for the help!

I dont have any screen shots, but there are some older diags on the USB I've found. (see attached).  do these state the serials of the drives and parity?

Backups.... not really.   Critical stuff is not on here, but its 14tb of collected data which I'd rather keep if possible.

 

dozer-diagnostics-20200205-0711.zip

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7 hours ago, isaw said:

I was installing additional 8TB drives and removing 2 empty drives at the sometime to my unriad server and when I hit new config. 

If your ultimate goal was to replace some smaller drives with larger drives you were going about it all wrong. Emptying disks and new config were completely unnecessary.

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Just now, trurl said:

If your ultimate goal was to replace some smaller drives with larger drives you were going about it all wrong. Emptying disks and new config were completely unnecessary.

it was.  I had 7 disks installed not realizing i had a 6 disk licence.  I wasn't able to save a config and when i turned off the server it seems I lost all the drive allocations.  Looking at it now I've fucked up pretty solidly.

 

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Your idea about XFS repair is probably not going to help. Rebuilding the disk from the correct parity and other disks assigned as they were the last time parity was correct is going to be the best hope.

 

It might be useful to use one of those new disks for the rebuild though and keep the original disk2 in reserve in case anything can be recovered from it.

 

Give us a while to study this new information and see what we can come up with.

  • Thanks 1
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1 minute ago, trurl said:

Your idea about XFS repair is probably not going to help. Rebuilding the disk from the correct parity and other disks assigned as they were the last time parity was correct is going to be the best hope.

 

It might be useful to use one of those new disks for the rebuild though and keep the original disk2 in reserve in case anything can be recovered from it.

 

Give us a while to study this new information and see what we can come up with.

Thanks.

Off to bed now before its my birthday tomorrow... what a present! 

I can try to put all the old drives back in and see waht it will look like for a rebuild, but I'd still like to try and figure out what drive is the correct parity drive and whats the data drive. 

 

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It looks like the correct drive assignments are:

Jan 11 20:04:44 Dozer kernel: md: import disk0: (sdd) WDC_WD80EFAX-68KNBN0_VAK5ZK3L size: 7814026532 
Jan 11 20:04:44 Dozer kernel: md: import disk1: (sdc) WDC_WD80EFZX-68UW8N0_R6H1KKHY size: 7814026532 
Jan 11 20:04:44 Dozer kernel: md: import disk2: (sdb) WDC_WD80EMAZ-00M9AA0_VAG2DXEL size: 7814026532 
Jan 11 20:04:44 Dozer kernel: md: import disk3: (sde) WDC_WD10EACS-00D6B0_WD-WCAU40301372 size: 976762552 
Jan 11 20:04:44 Dozer kernel: md: import disk4: (sdf) WDC_WD10EACS-00C7B0_WD-WCASJ1280244 size: 976761492 

 

3 minutes ago, isaw said:

Off to bed now

Let us know when you are ready to proceed. Don't do anything without us.

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33 minutes ago, isaw said:

following that I'd like to retry to correct the file system back to xfs,   and maybe then try to rebuild from the parity.

I do have some question about this statement though. What do you mean when you say "RETRY to correct the filesystem"? Did you try XFS repair on any of the disks?

 

And you have it exactly backwards, rebuilding from parity (with the invalidslot command in this case), then correcting filesystem if necessary will be the way to go. Rebuilding after correcting filesystem would just rebuild back to before the filesystem was corrected.

 

Another thing I noticed earlier in your comments

7 hours ago, isaw said:

repair for XFS on both the parity and the data drive

Parity has no filesystem so XFS repair of parity makes no sense.

 

39 minutes ago, trurl said:

replace some smaller drives with larger drives

For future reference, just replacing a smaller disk with a larger disk and rebuilding one at a time was the correct way to go here. The contents of the original disk would have been rebuilt onto the new disk so emptying a disk isn't needed.

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8 hours ago, trurl said:

It looks like the correct drive assignments are:


Jan 11 20:04:44 Dozer kernel: md: import disk0: (sdd) WDC_WD80EFAX-68KNBN0_VAK5ZK3L size: 7814026532 
Jan 11 20:04:44 Dozer kernel: md: import disk1: (sdc) WDC_WD80EFZX-68UW8N0_R6H1KKHY size: 7814026532 
Jan 11 20:04:44 Dozer kernel: md: import disk2: (sdb) WDC_WD80EMAZ-00M9AA0_VAG2DXEL size: 7814026532 
Jan 11 20:04:44 Dozer kernel: md: import disk3: (sde) WDC_WD10EACS-00D6B0_WD-WCAU40301372 size: 976762552 
Jan 11 20:04:44 Dozer kernel: md: import disk4: (sdf) WDC_WD10EACS-00C7B0_WD-WCASJ1280244 size: 976761492 

 

Let us know when you are ready to proceed. Don't do anything without us.

Ok. the WD 1tbs are installed.

image.thumb.png.67353ca2862dd3d48b35b72e1c06af1c.png

Array started in maintenance mode, with the drive allocations as posted above.

 

Next steps?

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1 minute ago, trurl said:

While we wait on a reply from johnnie, answer this question from earlier:

 

https://wiki.unraid.net/index.php/FAQ#What_if_I_accidentally_assign_a_data_drive_to_the_parity_slot.3F

 

Whilst I cant find the thread for it,  I'd assume since the data drive was assigned as parity for all of 90 seconds and only lost its xfs partition (the data on the disk isnt overwritten yet) there might be a way to recover it.    I havent tried to do anything yet but I would assume the testdisk tools/similar would be able to recover most of the data on the data drive as its not been overwritten with parity info yet.

 

I've NOT tried any repair or recovery on any disks.     I realized what I did, stopped the array from rebuilding and posted this thread.

nothing has been started in a full write array, only maintenance modes.

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3 minutes ago, isaw said:

I'd assume since the data drive was assigned as parity for all of 90 seconds and only lost its xfs partition (the data on the disk isnt overwritten yet) there might be a way to recover it.

What we would like to do is not rely on anything already on the disk, but instead rebuild it from the parity calculation using the original parity and all the disks that parity is based on. In fact, as mentioned earlier:

9 hours ago, trurl said:

It might be useful to use one of those new disks for the rebuild though and keep the original disk2 in reserve in case anything can be recovered from it.

 

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7 minutes ago, trurl said:

What we would like to do is not rely on anything already on the disk, but instead rebuild it from the parity calculation using the original parity and all the disks that parity is based on. In fact, as mentioned earlier:

 

Yep.  I can swap a disk out if need be, but I was just thinking it might be easier/quicker to see what can be recovered from the disk before going down the rebuild from parity path.

 

I'll wait for your advice on next actions.

 

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It's already Saturday night where @johnnie.black lives, so we may be waiting a while on him.

 

The reason I think you want to rebuild from parity is because I think that is likely to have a better result after what happened. Even with the rebuild there may be some filesystem repair to do on the rebuilt disk.

 

Doing the rebuild on a new disk will still allow you to work with the original disk later and independently from that rebuild. The results from a filesystem repair can sometimes be pretty ugly, and that is what I expect if you attemp to repair the original disk after what happened.

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18 minutes ago, trurl said:

It's already Saturday night where @johnnie.black lives, so we may be waiting a while on him.

 

The reason I think you want to rebuild from parity is because I think that is likely to have a better result after what happened. Even with the rebuild there may be some filesystem repair to do on the rebuilt disk.

 

Doing the rebuild on a new disk will still allow you to work with the original disk later and independently from that rebuild. The results from a filesystem repair can sometimes be pretty ugly, and that is what I expect if you attemp to repair the original disk after what happened.

The disks spare are my old raid 5 array, and as of right now they still have the data on them (ie my backup).

if i was to overwrite one of them i'd lose that array, hence my desire to go down the path of using the current disks just incase i need to pull all those drives back into a box, recreate the raid and then move the data from it.  

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