Lennart KoopmannJun 15, 2023

I've been running Linux for 15 years and am stuck. Help!

On Ubuntu Desktop, sometimes (usually after a few minutes - sometimes not at all until reboot) all file write operations seem to hang, while opening files is not a problem. Can't kill processes, they just go <defunct>. Extremely slow drawing of windows.

What's going on here? Memory and CPU look good. Open files are not crazy... io load is very low. Not virtualized.

Any ideas?

Show threadVissJun 15, 2023
@_lennart you could be hanging up on too many open files or some kind of disk io? could try vmstat to check?
Show threadVissJun 15, 2023

@_lennart its also possible you have a crummy disk and either
A) its got bad sectors, so syslog will scream at you
B) its having cache issues and getting stuff from actual storage to the OS is choking because of the disk cache.

or, and this hits me from time to time
the stupid fucking local resolver bullshit i always forget to turn off makes everything wait while it does a dns lookup for your machines hostname, which will never resolve, so you get to wait.

Show threadLennart KoopmannJun 15, 2023
@Viss omg I swear to god if this is a systemd DNS thing haha
Show threadVissJun 15, 2023
@_lennart tail -f /var/log/syslog then try and recreate the problem ;b
Show threadLennart Koopmann
@Viss have it tailing, waiting for things to happen again
Jun 15, 2023 at 2:34amWeb
Show threadnoahmJun 15, 2023
@_lennart @Viss `dmesg -w` may be more reliable, if disk IO is a concern. With the syslog files being, you know, on disk and everything. Also, haven’t modern Ubuntu releases moved most logging to the systemd journal? `journalctl -f` might be better in that case.