[6.12.3] How do I...? Parity Check vs Data Rebuild vs Mover

[interwebtech]

This is combined "possible bug" report and request for guidance on correct settings.

 

Before a recent change in behavior I had Mover set to not run if a parity check (it also applied to data rebuild) was in progress. I prefer this method.

 

The new behavior has the parity check pause then letting mover run and then resuming the parity check once mover completes. Notifications sent at each step of the process. I experienced this recently with my scheduled quarterly automatic parity check.

 

Fast forward to now... I am at the tail end of a data rebuild (larger disks replacing old array members) and I notice the behavior is slightly different. Mover runs on schedule but data rebuild is NOT paused (at least GUI doesn't indicate it is). No notifications sent (logical since no pause occurred?). Rebuild drops to 3mbps and shows completion expected in several days. Note it was at 97.5% complete when this occurred. I let this process continue figuring maybe an hour or so to move roughly 50GBs (guessing). Several hours later and its still not done yet. This is when I noticed that the rebuild had not been paused before the mover started. At that time I manually paused it. Files were finally moving at a faster pace and should be done shortly. Side note I earlier shut off plex docker & Roon server;  external NUC reads unRaid share where music files live; when I noticed they were both running file read/processing maintenance that was likely causing some contentention with the rebuild AND mover also running. 

 

Okay so bug report is regarding the different behavior between a parity check vs data rebuild and scheduled Mover runs. I would think they would be consistent (pause, send notifications, etc). 

Second, how to I configure this new behaviour to NOT pause parity checks or data rebuilds for Mover runs. I prefer the array operations complete as quickly as possible. I want Mover disabled when the array is doing either of these. It used to be a single checkbox that did that.

 

Diagnostics attached. Note these were gathered while data rebuild was manually paused and mover was finishing up its run.

 

 

tower-diagnostics-20230717-0750.zip

 

PS. I have the Parity Check Tuning plug-in installed

Edited July 17, 2023 by interwebtech

[itimpi]

9 minutes ago, interwebtech said:

Before a recent change in behavior I had Mover set to not run if a parity check (it also applied to data rebuild) was in progress. I prefer this method.

This is a setting in the Mover Tuning plugin, so set it if you want this behaviour.   However I do not know if it ever has applied to other array operations although you suggest it did.   You should ask in this plugins support thread if you think it has changed.

 

10 minutes ago, interwebtech said:

The new behavior has the parity check pause then letting mover run and then resuming the parity check once mover completes. Notifications sent at each step of the process. I experienced this recently with my scheduled quarterly automatic parity check.

This is not new behaviour - it is just that some bugs in the Parity Check Tuning plugin that could stop this behaviour working properly have been corrected.   It is controlled by a a setting in the Parity Check Tuning plugin so if you do not want this behaviour then you can switch it off in the plugin’s settings.  In most cases it is more efficient to pause the Parity Check while mover is running as the two processes both badly adversely affect each others performance.   It is obviously only relevant if mover DOES start while a parity check is already running which is outside the control of this plugin.

I thought the Parity Check Tuning plugin should also apply this behaviour if set for all array type operations so I need to work out why it has not done so in your case.