Strange Disc I/O

run

apt-get install iotop; iotop

It's like top just for disk io.

@obs:

run iotop
Cool! However my linode just quit doing disc use again; sorting by reads or writes all show 0 B/s.

I'll have to wait until it starts up again.

It seems like it may be doing this activity only on idle.

Check your crons as well, could be something like log rotate, updating the locate database etc etc

By the way, single-digit I/O numbers are next to nothing. Those bumps would have been invisible if your site had a moderate level of traffic. The 24-hour cycle suggests that it has something to do with cron or log rotation, but even if you don't find the cause, you don't need to be worried.

@obs:

Check your crons as well, could be something like log rotate, updating the locate database etc etc
Crons didn't show anything out of the ordinary from what I could tell, but see below…

@hybinet:

By the way, single-digit I/O numbers are next to nothing. Those bumps would have been invisible if your site had a moderate level of traffic.

Sounds good! Even when the graph shows activity (aka, right now), there's nothing going on in iotop. Occasionally I get a blip from "kjournald," which appears to be the EXT3 journaling daemon: link. Another couple blips from "syslogd," which is apparently a logging utility daemon: link.

I guess this probably goes on all the time, and I'm just noticing it because I have fine-grain tools to see it. I'm betting this sort of stuff goes on all the time on my Windows box and I just don't notice :lol:

Thanks for your help!