Parity confusion

[columbuscoltsfan]

After adding a bunch of files to my server, and wanting to guarantee that they wont be lost in the future, should I run a parity check (for first time since adding files) with "write corrections to disk" checked, or not checked?

 

And should I not be downloading or adding files during the parity check?

Edited June 11, 2019 by columbuscoltsfan

[itimpi]

It should not be necessary to run a parity check as Unraid updates parity in real-time, but you can run one if you would feel happier.   Most people run one at most once a month just as part of standard housekeeping.

 

Downloading or adding files (or even reading files) during a parity check is allowed but it adversely affects the performance of the check due to disk contention.

[JonathanM]

6 minutes ago, columbuscoltsfan said:

guarantee that they wont be lost in the future

Make a backup in a different place. Parity is not a backup, and can't restore your files from corruption, deletion, or overwriting. It can only reconstruct an entire drive using all your other data drives in case of a single drive failure.

 

Parity doesn't have any concept of files, so as long as parity was written correctly in the first place, it should still be valid. Normally we schedule non-correcting parity checks once a month to catch any glitches, if you want to run one just because, you certainly can. You can still use the array during a check, but it will be slower, possibly much slower.

 

If there are any errors found during a check, post back with your diagnostics. Zero errors is the only acceptable result.