can I disable raid-check? (md raid linux)

[Red Squirrel]

I noticed on newer distros there is this raid-check thing that runs almost every day, and it brings the server to it's knees. Is there any reason why this has to run? Can I just disable it completely? I fond the cron job for it, it's in /etc/cron.d/raid-check. Removed it completely and put it in the regular cron tab and set it to once a year, but then I thought, do I even need it? My old server never had it running.

 

[drescherjm]

I would do that 1 time a week to ensure your drives are readable.

 

[uOpt]

Removing it entirely is unwise. You really want to find unreadable blocks and have the RAID system correct them while the RAID is not degraded. Otherwise bad things happen if you are degraded, have to re-sync and *then* hit unreadable blocks.

I agree completely that simply turning it on in a cronjob and making the major unusable for extended periods of time isn't good.

My md raid are in partitions max 1 TB/disk, and I start those when I know the machine is idle-ish. I also give very high(!) priority to the test so that foreground activity doesn't slow it down. If you have eg. the chrome browser messing with the filesystem all the time you can delay the check indefinitely with the default, which is give priority to real work.