auth.log file has suddenly grown and filled up the partition

[HalationEffect]

Like the title says, the file /var/log/auth.log is using up all the free space (over 4GB) on my root partition, and I can't do any system updates as a result.

Discovering that it's the auth.log file that has bloated up and consumed all the free space is pretty much the limit of my own troubleshooting abilities.

[claydoh]

RThis log file tracks any login and other authorization actions - sudo, ssh, and other things in that nature.
You might try poking around the log file to see what is going on.
https://www.digitalocean.com/communi...logs-on-ubuntu
if you happen to have KSystemLog installed, you can view the log with this tool.

You can try clearing the file (not deleting, though that might also be fine to do):

sudo cat /dev/null > /var/log/auth.log

After that, you can keep an eye on it easier, and look at the contents when they are not so large, to see what is happening, and see if there is anything that sticks out - and is easier to find the bits to copy/paste .

[HalationEffect]

Using KSystemLog, I can see that the auth log is being spammed with the following:

[system] Rejected: destination has a full message queue, 0 matched rules; type="error", sender="(unset)" ((bus)) interface="(unset)" member="(unset)" error name="org.freedesktop.DBus.Error.ServiceUnknown" requested_reply="1" destination=":1.41" (uid=1000 pid=1507 comm="/usr/bin/kwin_x11 -session 10878237300001636390643" label="unconfined")

When I enter the command to clear the log, i get:

bash: /var/log/auth.log: Permission denied

That response is immediate - it doesn't even ask for the sudo password.

[claydoh]

Make that

sudo su
cat /dev/null > /var/log/auth.log

What is to the left of the error message spam?

[HalationEffect]

Thank you, claydoh! Reducing that log down to a zero byte file allowed me to perform some pending system updates (including a kernel update), and the auth.log doesn't seem to be getting hammered any more... I'll keep an eye on my root partition's free space to make sure.

I'm uncertain what you mean by "to the left of" the error spam. KSystemLog showed me a list of messages, and I double clicked one of them to see its contents, then copied & pasted it into my 2nd post.

[claydoh]

The column to the direct left of the message, which is the process. It would help narrow down the specific item spamming the log, which hopefully points to a cure, fix, or workaround if it fills up again.

[HalationEffect]

The offending process is dbus-daemon[834]

I thought it had stopped, but it just seems to be filling up the log fairly slowly.

[claydoh]

Nvidia driver?
If so, which version?

mebbe:
https://www.reddit.com/r/kde/comment...emon_and_kwin/
which goes to
https://forums.developer.nvidia.com/...ages/192892/26

No idea if this works, or it is better to downgrade Nvidia, or try and move to a newer beta driver, if available in Ubuntu.

[HalationEffect]

Nvidia 495.46 driver in use here. Upgraded it over the weekend, so the time-frame fits.

I think I'll probably just go back to the 470.xx driver and see how that goes.

* * *

Edited to add that rolling back the Nvidia driver went smoothly and has put an end to the log spam.