During the recent monthly scan I had many errors showing up, not sure if it’s a current data issue? 

tower-diagnostics-20230703-1043.zip

Had you had any suspected unclean shutdowns or anything else that might indicate you should expect some errors?  I notice that disk3 and disk6 indicate in their SMART information that they may have had connection issues at some point as they have non-zero values for the UDMA CRC attributes.  This may be a red herring as since this attribute never resets to zero it could be quite an old issue.   You might want to consider, however, running a check filesystem on the array drives to make sure none of them seem to have any current file system level corruption.

 

I also notice that you seem to have the regularly scheduled scan set to be correcting.   It is normally recommended that this scan is set to be none-correcting so that you do not have a drive that is playing up inadvertently corrupting parity.   You normally only want manually initiated scans to be set as correcting as that gives you a chance to look into why a scheduled scan is reporting errors before any changes are made to parity and only issuing correcting checks when you are confident there are no obvious hardware issues.

So there are no unexpected shutdowns. The drive replacement was done successfully. And one month later this thing happened. Not sure why? Either parity drive was corrupted or some other drives were corrupted?

I will try the link you provided and report back. 
 

As for the parity correcting thing you mentioned, I think it is the default setup I’ve been since using since 5.x. Did something change? 

 

3 hours ago, CyberMew said:

As for the parity correcting thing you mentioned, I think it is the default setup I’ve been since using since 5.x. Did something change

I don’t think the recommendation has changed 😊. As to whether the default setting has changed I am not sure :😒

1 minute ago, itimpi said:

I don’t think the recommendation has changed 😊. As to whether the default setting has changed I am not sure :😒

Oh hmm I don’t think I changed something like this.. I did remember someone saying it’s supposed to write if during parity check there were errors, since there’s no way it can be fixed anyway..

How can I verify my setting and change it back to default?

Just now, CyberMew said:

Oh hmm I don’t think I changed something like this.. I did remember someone saying it’s supposed to write if during parity check there were errors, since there’s no way it can be fixed anyway..

How can I verify my setting and change it back to default?

Just go into Settings->Scheduler and set it to be non-correcting.   I would not worry if that is the default or not.

 

you are correct that if there are no hardware issues there is not much you can do except run a correcting check.    What you do not want, however, is to run a correcting with a drive playing up which can then lead to parity getting corrupted/made invalid thus prejudicing later recovery