Today the hard drive of our server was suddenly full. The disk usage always stayed around 50 % in the weeks and months before (old data is regularly expunged from the server).
I deleted 10 GB of files in /tmp, which strangely freed 51 GB. Here is what I did:
root@***:~# df -h
Dateisystem Size Used Avail Use% Eingehängt auf
/dev/sda3 139G 137G 0 100% /
tmpfs 3,9G 0 3,9G 0% /lib/init/rw
udev 3,9G 116K 3,9G 1% /dev
tmpfs 3,9G 0 3,9G 0% /dev/shm
/dev/sda1 985M 25M 910M 3% /boot
root@***:/var# du -hs *
3,3M backups
438M cache
9,4G lib
4,0K local
12K lock
76M log
24K mail
4,0K opt
88K run
184K spool
10G tmp
12K www
root@***:/var/tmp# find -type f -print0 | xargs -0 rm
root@***:/var/tmp# df -h
Dateisystem Size Used Avail Use% Eingehängt auf
/dev/sda3 139G 81G 51G 62% /
tmpfs 3,9G 0 3,9G 0% /lib/init/rw
udev 3,9G 116K 3,9G 1% /dev
tmpfs 3,9G 0 3,9G 0% /dev/shm
/dev/sda1 985M 25M 910M 3% /boot
Any explanation as to why deleting 10 GB in /tmp gave me back 51 GB on the disk? Could this point to an SSD failure? Are there any tools for Debian to test SSD health?
I already have checked syslog. The first entry relating to this incidient is a mysql message:
1:22:02 [ERROR] /usr/sbin/mysqld: Disk is full writing...
So I have absolutely no idea what caused this.