How long should I expect Parity to take

[Stephenph]

Just want to see how long I should expect my parity to run in general.  Currently have a 1 disc array and a single Parity drive (both drives are WDC_WD30EFRX-68AX9N0_WD-WCC1T1090948).  In addition I have a single SSD  cache drive (WDC_WDS100T2B0A-00SM50_190235458402 )

 

The array is only  at about 2% utilization at this time, but I do plan on uploading a lot more data soon.  The parity check is scheduled for every week and is ran when the system is not in active use (2 AM on Monday morning)

 

Currently the parity check takes about 7.5 hours.  Will the parity check take longer with more data on the array?  are there tweaks I can do to make it faster?  My current plan is to add a second Cache pool  (Probably a pair of NvME drives)  in a few months  (sooner if warranted) and a second hard drive when my array is storing about 2 TB.

 

 

 

[JorgeB]

8 minutes ago, Stephenph said:

Will the parity check take longer with more data on the array?

Nope, and 7.5h sounds about right for the model and capacity of the disks involved, usually count with 2 to 3h per TB.

[JonathanM]

5 hours ago, Stephenph said:

The parity check is scheduled for every week

Why so often? Default is once a month, typically that's enough.

 

Parity checks are only needed to verify that parity is being kept up to date, and they are useful to ensure that seldom used disks are still completely error free so if a drive fails it can be successfully rebuilt. Parity is kept up to date in realtime, checks are only needed to verify the realtime process is still working as it should.