This problem just started a week ago...
When I first boot up and log in, ROOT (system files) is 51% free space. I will leave it sit over night, not doing nothing to it. And in the morning I will have a WARNING window saying LOW disk space on ROOT. 1.2Gb or lower. The partition was formatted 30Gb.
I clean up my TEMP file but not that much about 150Mb. I clean up my JOURNAL files down to 200Mb. Daily. I clean out APT cache and clean up SNAP files. Daily.
This keeps happening on a daily basis. What more can I do, and why is this happening every day? I have left the system on for weeks on end and never had this problem.
Any and all HELP is appreciated.
THANKS.
P.S. HOME is on it's own partition. And SWAP also.
I ran your command suggestion, I don't understand the output. What am I looking for?
OUTPUT:
administrator@MATE:/$ ls -of
lib64 etc run snap .. . dev lost+found usr proc sbin libx32 sys home opt tmp boot mnt root lib32 bin var media lib srv cdrom
These outputs were at the top of the list, and the highest write figures:
270 be/3 root 0.00 B 2.80 M ?unavailable? [jbd2/sda7-8]
317 be/3 root 8.00 K 204.64 M ?unavailable? systemd-journald
638 be/3 root 0.00 B 1700.00 K ?unavailable? [jbd2/sda8-8]
945 be/4 syslog 0.00 B 13.37 M ?unavailable? rsyslogd -n -iNONE [rs:main Q:Reg]
See anything out of place or strange? This was for a 10 min. period.
I think this explains why my JOURNAL files are so big.
Do I get it right that you have already found out that disk space is consumed by journal files?
If yes, I'd try to find out what are messages which overflow journals and eliminate the reason. You see, I've stumbled upon cases when log files grow endlessly due to a lot of errors reported by background process.