4x the normal speed parity check?

[danimal86]

I just upgraded from 6.9.2 to 6.10.3 about a week ago and a few days ago it ran its first parity check.  I had it set to do the Cumulative Parity check to start at midnight on the 1st of the month and run for 6hrs.

 

I noticed at about 6:30 am on the 1st that the parity was still running, didn't really worry too much about it.  Today i go in and check in on the server and see that it finished the parity check in 7hrs.  I'm running two 16tb WD Golds as parity and never have seen it this fast before at a whopping 585 MB/s.  Usually it always runs around 130-140 MB/s.  

 

 

What the hell is going on?  Is there some magic sauce in 6.10.3 that makes parity run 4x as fast?

[JorgeB]

11 hours ago, danimal86 said:

Is there some magic sauce in 6.10.3 that makes parity run 4x as fast?

No, that's an impossible speed, likely the check is just accounting for the last time it an, but considering the full parity size for the speed average.

[Frank1940]

I believe the math is screwed up when you do the Cumulative Parity.  I have notice the same thing.  I suspect the formula is using the  total bytes checked divided by the time for the current session (rather the cumulative time for all the sessions). 

Edited July 5, 2022 by Frank1940

[danimal86]

1 hour ago, Frank1940 said:

I believe the math is screwed up when you do the Cumulative Parity.  I have notice the same thing.  I suspect the formula is using the  total bytes checked divided by the time for the current session (rather the cumulative time for all the sessions). 

That would make sense.  I'll probably just switch it off of the cumulative check, i dont think it worked since i saw it running the parity check past 6am.   

 

7 hours ago, JorgeB said:

No, that's an impossible speed, likely the check is just accounting for the last time it an, but considering the full parity size for the speed average.

Yeah, but damn, that would be nice to get speeds that fast.  

[itimpi]

3 hours ago, danimal86 said:

That would make sense.  I'll probably just switch it off of the cumulative check, i dont think it worked since i saw it running the parity check past 6am.   

You could use the Parity Check Tuning plugin instead.   That is more flexible and does everything the cumulative check does and much more.   It also (although not relevant here) runs on earlier Unraid releases.