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Somehow my work-in-progress Python server filled the rootfs partition by logging 50gb of data to /tmp/blabla.log, which I noticed by basic commands failing like this: root@server:/# crontab -e /tmp/crontab.FfvjqH: No space left on device
So, I did rm -rf /tmp/blabla.log and the file disappeared, cannot be seen with ls or tail... but the insufficient space errors persist. df -h still reports that rootfs is 100% used and does not reflect that I removed the 50gb file.
I could free some more space by moving some files to another parition and the system is OK but I don't have my 50gb of free space back.
What could be the problem?
my own answer: After moving some 3gb of files from the rootfs partition, I dared to restart the server, at the risk of having the server nog restart due to disk-space problems, but luckily it rebooted successfully and after reboot df -h reported the correct amount of free space. So system reboot seemed to be the answer.