One of my drives (Disk 17) went offline recently and had issues trying to get it to rebuild. The rebuild was really slow going to less than 1MB/sec although would start at more normal speeds. 

 

I did some testing (running Diskspeed docker and moving drives around) and actually narrowed the issue down to Disk 16. I run dual parity to removed Disk 16 from the array and then rebuilt Disk 17. The rebuild was fine and I started the process of RMAing Disk 16. 

 

I got my warranty replacement today and put in my new Disk 16 to rebuild the array. I started it last night at around midnight and came down this morning to see that the rebuild was paused at around 55%. I started the rebuild again and it started rebuilding but at around 8MB/s and then paused again. 

 

I'm a little lost at what the issue might be now as I'd assumed it was the disk itself that was the issue. I tried the old Disk 16 in different slots in my case and also a external USB 3 dock and had the same issue each time! 

 

Have attached my diagnostics. Any ideas as to what the issue might be as I am lost.  

*edit* just resumed it again and is running at around 190MB/s.

tower-diagnostics-20250125-0847.zip

Edited January 25, 20251 yr by ekim

Try disabling the parity tuning plugin, it may be misconfigured, making it pause.

Thanks I've removed it for now. The rebuild speed seems to be holding at the moment. 

17 minutes ago, ekim said:

Thanks I've removed it for now. The rebuild speed seems to be holding at the moment. 

Looking at the settings for the parity check tuning plugin in your diagnostics you did not have it set to run rebuild in increments but you did have it set to pause the rebuild if mover or appdata backup were running.   Do you have anything in your notification history from the plugin that suggest it is pausing the rebuild and giving the reason?  Would like to know so that if it was pausing the rebuild when it should not then I would like to try and work out why as that would be a bug that should be fixed.

These are the notifications - looks like it could have been partity check tuning pausing things. Not sure why the speed was coming back so slow though. But everything is ticking along ok again at the moment. 

 

Looks like the plugin was might have been pausing the rebuild because mover was running and you had it configured to do that.   That could also explain why the rebuild was going slow as mover and any array operation running at the same time badly degrade each others performance.   

 

I will look into adding a bit more detail to the Paused notification so it is clearer what triggered the pause. There is no 'resume' after the plugin detected that mover had finished so it is possible the pauses were not triggered by mover running (and I have a bug to look into).  I have logic to suppress the 'mover' running one repeating unnecessarily (which I think is the reason you were getting pauses) and I assumed it would normally be obvious when the pause followed a notification that mover was running but adding that extra information to the pause itself would make it clearer.   

Great thanks. The rebuild is still going so happy that it is all working fine. The old drive that I replaced was causing all sorts of other issues so confident this was just a small blip due to parity tuning.