What is the impact of read/writing to a server during a parity check? Is there any issue or risk of data or parity corruption for writing to the array before the check completes? Or is read/write speeds just slower during this process?

 

Thanks for indulging the novice question.

The last... No problem in using the array during parity checks.. It will impact speed.

Got it. Could you in theory cancel a parity check to improve speeds temporarily, then run the full parity check later on?

 

Or would that introduce possible parity corruptions since you'd be writing to the server temporarily without a valid party in place?

Parity is still valid during a check.  It wouldn't be valid during creation.

Got it. Could you in theory cancel a parity check to improve speeds temporarily, then run the full parity check later on?

 

Or would that introduce possible parity corruptions since you'd be writing to the server temporarily without a valid party in place?

"without a valid parity in place" would only happen if you had a new configuration, or just added a parity drive. Then you would have a parity build and it would be invalid until complete.

 

Even if you have parity errors that haven't been discovered yet because a parity check hasn't been done, parity is still considered valid because those errors are unknown.

 

While you are doing a parity check, you still have valid parity. Any writes you make to the array, whether it is doing a parity check or not, will update parity so it remains valid. I often have torrents running during the monthly parity check and have never had a problem with it.

 

So, you can cancel and do it later.

 

Does this still apply in the case of an accidental unclean shutdown? The parity check auto-starts when I restart the array.

Does this still apply in the case of an accidental unclean shutdown? The parity check auto-starts when I restart the array.

In that case your parity is still considered valid, but it is more likely that there are parity errors. I think that is the only time I have had parity errors.

 

You can still cancel, but you should do a parity check soon because if you do need to rebuild a data drive you need all of your parity to be correct.

 

And of course, you can still use the array while an auto parity check is in progress.

Thanks guys.