First build of Parity errors and very slow

[chrismex]

Hi All,

 

I am new to Unraid and have built a system, tranfered all of my data across added some extra drives and a cache then added a parity drive. I left the system to do the initial parity check over night and have come back to one of the drives having read errors and the parity sync dropping from around 100-150MB/s to 8-9MB/s. I have attached the diagnostics and can see that one of the drives has read errors but want to know what is my best option to resolve this. I understand the drive will likely need to be replaced but is it possible to get a parity build with all of the readable data on that drive so i can rebuilt and not lose everything on it.

odin-diagnostics-20220405-1019.zip

[JorgeB]

5 minutes ago, chrismex said:

I understand the drive will likely need to be replaced

Looks like it does.

 

5 minutes ago, chrismex said:

is it possible to get a parity build with all of the readable data on that drive so i can rebuilt and not lose everything on it.

It's possible, but parity won't be 100% valid, so if you then replace the disk the rebuilt disk will have some data corruption, unless the read errors are in empty disk space.

[chrismex]

Would it cause issues if i stop the parity check then move the data from that drive to a new empty one in the array from media/disk2 to media/disk7 ? Then i could run checks on the drive and maybe a preclear to see if there are fixable errors on the drive or rather than running checks should i just replace that drive?

[JorgeB]

You can do that, though it's possible some data fails to copy/move, but at least you'll know which data is affected, another option is to use ddrescue to recover as much as possible.

[chrismex]

I have managed to move all of the data from the drive to another without any issues so looks like the read error is in an area that wasnt being used yet thankfully.

 

While the parity is building for this array is it ok to set up my docker apps and have them start writing data back to the array or is it best to wait until the initial parity check has completed?

[JorgeB]

Setting up docker is fine, I would avoid writing data to the array.

[chrismex]

I thought as much, i will leave the configuration of dockers until tomorrow when the parity will hopefully have built ok, thank you for all of your help today.