On my Ubuntu 21.10 Ubuntu desktop, which is sometimes on at midnight (if I happen to be awake and using it), a nightly event takes place where there is a lot of disk activity -- the red light for the HDD is blinking repeatedly, even though I'm not doing anything. I don't know what it is, but it does cause the system to slow down.
I know it isn't a user-level or a root-level cronjob. I've checked that. So, I guess it's something that has been turned on by default. I suppose I also have a slight concern that it's something done by an outside party, but I guess that's unlikely since midnight every night is a bit too predictable.
I have set up a backup program, but that program doesn't run at midnight. It's possible it's just rotating log files or something. Whatever it is, I just want to know what it is (and maybe move it to another time).
Anyway, what can I do to figure out what's causing this? I have looked at the output of top
, but nothing looks out of place. Besides the user and root's crontab
, is there anything else I should check?
Any suggestions would be appreciated!
htop
) during this time, and see which process consumes most CPU?systemctl list-timers
(maybe alsocrontab -l
) the list of timers. They will also show you when they start againsystemctl list-timers
. (It wasn't anything I set incrontab
, though.) Combined with the answer below, I was able to find the culprit to bemlocate
. Thank you!