Undo New Config?

[jakeisrollin]

Hey everyone, so i did a few dumb things today

 

the SATA cable on one of my hard drives snapped off so i had to remove the drive. when i got into unraid I was unable to start the array because one of the data disks was missing and i couldnt unassign the disk.

 

i googled how to shrink array, i came to this guide and did up to step 7. this is where i realized i should have read up on this a bit more, i can start the array now but my parity drive says 'all existing data on this device will be overwritten when array is started'. the data disk does nopt have any messages but now im worried that i will have to format it when i start the array.

 

am i out of luck or can i still save my data? also, i have my appdata on a ssd, will this data be safe or is it also gone?

 

I have the following

1 x 14 TB parity drive

1 x 6 TB data disk

1 x 6 TB data disk (removed)

 

the parity drive is new, just installed a few days ago and the parity was rebuilt like yesterday, idk if that matters at all.

[JorgeB]

Parity will be re-rynced so it will be overwritten, data on the remaining disks won't be touched, in case you're not aware any data on the removed disk will also be missing, but that's normal with an array shrink.

[apandey]

Is your other drive physically damaged or it's just a cable problem? I am not sure why you are removing that drive rather than connecting it back

 

If you shrink array, and the removed drive is not readable, you will have no way to recover the data from the removed drive

 

If you want to recover data, keep configuration and parity intact, start the array and see if the broken drive is emulated and then copy over the data to the remaining drive. Of rebuild the broken data drive by replacing it. Once parity is overwritten, you won't have any of these recovery options 

[jakeisrollin]

  

21 hours ago, JorgeB said:

Parity will be re-rynced so it will be overwritten, data on the remaining disks won't be touched, in case you're not aware any data on the removed disk will also be missing, but that's normal with an array shrink.

 

ok so when i start the array should i leave the checkbox that says 'parity is already valid' unchecked? If i have to re-do parity i dont really mind i just dont want to lose my appdata and if i can save my data that would be cool to. i did find another post that said start with that option checked and wait to see if unraid recognizes the disks but ive been hesitant to try 

 

 

20 hours ago, apandey said:

Is your other drive physically damaged or it's just a cable problem? I am not sure why you are removing that drive rather than connecting it back

 

If you shrink array, and the removed drive is not readable, you will have no way to recover the data from the removed drive

 

If you want to recover data, keep configuration and parity intact, start the array and see if the broken drive is emulated and then copy over the data to the remaining drive. Of rebuild the broken data drive by replacing it. Once parity is overwritten, you won't have any of these recovery options 

 

the plastic L piece that the cable snaps into broke off and i wasnt able to get the cable back in place with out damaging the pins. i figured if the pins are good theres a shot of saving it but idk really, heres what it looks like now

 

 

i would like to save my data if i can, if i go on it now theres a checkbox that says 'parity is already valid' i found another post that said start with that checked and wait to see if unraid recognizes the disks but i guess im a little worried about just doing it after what happened yesterday lol

Edited May 10, 2023 by jakeisrollin

[JorgeB]

3 hours ago, jakeisrollin said:

ok so when i start the array should i leave the checkbox that says 'parity is already valid' unchecked?

You must because parity is no longer valid with a missing disk, and like mentioned you you'll lose any data on the missing disk.

 

 

[itimpi]

4 hours ago, jakeisrollin said:

If i have to re-do parity i dont really mind i just dont want to lose my appdata and if i can save my data that would be cool to

Rebuilding parity does not touch the other disks so your appdata should be intact.

 

It is worth pointing out that by itself parity contains NO data.  It just has the information that is required to repair a failed drive (in conjunction with all the other drives that are OK).

[apandey]

2 hours ago, JorgeB said:

You must because parity is no longer valid with a missing disk, and like mentioned you you'll lose any data on the missing disk

isnt it that parity should be valid as of when the data disk broke and since then array has not been started, so parity should be untouched. so the only remaining question is whether missing disk can be added to the array in new config. i think thats the only issue, because if that could be done, this is just a case of a drive dying, then we using parity to emulate it

your response indicates there is no way to add back the new disk. 

 

in that case, i would assume unraid will lose data from broken disk. however, looking at the damage, its possible you can sleeve in the plastic part and bring the disk back up to try and copy over data. the connection may be flaky, but if no other option, i will give it a try

[JorgeB]

If the intention was to recover the data from the missing disk a new config should not have been done, in should have been a standard disk replacement, or move the data from the emulated missing disk to other array disk(s) then do a new config.

[apandey]

41 minutes ago, JorgeB said:

If the intention was to recover the data from the missing disk a new config should not have been done, in should have been a standard disk replacement, or move the data from the emulated missing disk to other array disk(s) then do a new config.

yes, and i think @jakeisrollin did realise that midway through his shrink attempt, hence the title of this thread wanting to undo new config

he did mention he wants to save data if possible, which is why i asked if he can rebuild. all but one drives are available with correct data, the only issue is broken config

[JorgeB]

If parity is still valid he can try this:

 

-Tools -> New Config -> Retain current configuration: All -> Apply
-Check all assignments and assign any missing disk(s) if needed, including the new disk you want to rebuild, replacement disk should be same size or larger than the old one
-IMPORTANT - Check both "parity is already valid" and "maintenance mode" and start the array (note that the GUI will still show that data on parity disk(s) will be overwritten, this is normal as it doesn't account for the checkbox, but it won't be as long as it's checked)
-Stop array
-Unassign the disk you want to rebuild
-Start array (in normal mode now), ideally the emulated disk will now mount and contents look correct, if it doesn't you should run a filesystem check on the emulated disk
-If the emulated disk mounts and contents look correct stop the array
-Re-assign the disk to rebuild and start array to begin.

[jakeisrollin]

17 hours ago, JorgeB said:

If parity is still valid he can try this:

 

-Tools -> New Config -> Retain current configuration: All -> Apply
-Check all assignments and assign any missing disk(s) if needed, including the new disk you want to rebuild, replacement disk should be same size or larger than the old one
-IMPORTANT - Check both "parity is already valid" and "maintenance mode" and start the array (note that the GUI will still show that data on parity disk(s) will be overwritten, this is normal as it doesn't account for the checkbox, but it won't be as long as it's checked)
-Stop array
-Unassign the disk you want to rebuild
-Start array (in normal mode now), ideally the emulated disk will now mount and contents look correct, if it doesn't you should run a filesystem check on the emulated disk
-If the emulated disk mounts and contents look correct stop the array
-Re-assign the disk to rebuild and start array to begin.

 

this worked for me, i started the array in maintenance mode and clicked on 'parity is already valid', then i stopped the array and restarted it again. most of my data was is there  it looks like i lost things from the last week or so but thats ok.

 

thank you guys really appreciate the help