Performance During Parity Check

[a12vman]

What is everyone's total processing time for parity check?

 

I have 26 TB spread over 4 Drives(10/6/6/4) with a 12TB parity drive.  

 

This usually takes ~ 26 Hours to complete.  

 

My server has dual Xeon x5675 with 64GB Ram.

 

Is the bottleneck Disk I/O?  My server CPU total is running at 10% during parity check.

 

CPU Utilization is always the same(whether running parity check or not running it).

It picks 1 virtual core and runs it at 100% for a few minutes, then idles and repeats on a different virtual core.

 

Just wondering if there are any secrets to decreasing the amount of time it takes.

 

I see lag time in accessing shares as well as studdering in video playback over Plex that goes away when parity check is complete.

 

I have looked at the Parity Check Tuning plugin but that is related to scheduling during of-peak time.

 

 

Edited April 5, 2020 by a12vman

[itimpi]

The time for a parity check is dependent primarily on the size of the largest parity drive - the sizes of the data drives has little effect.    The time you quote of 26 hours sounds not atypical for a 12TB parity drive - typically one estimates 2-3 hours per TB.    It is just that it takes a long time to read 12TB of data (since parity check reads every sector on the parity drive).

 

One of the reasons for the development of the Parity Check Tuning plugin was the fact that with the size of modern large drives there is no way of completing a parity check fast enough to avoid it impacting ones daily use.