I'm running Linux Mint 14 Nadia.  The Linux partition has 10G.  When the system starts, du reports 80% usage.  Then the usage slowly grows until it reaches 100% and the system becomes unusable.  (It can happen on the order of days or weeks).  After the reboot the usage resets to 80%.The strangest thing of all is that du shows no change.  Here's output of those commands (Windows and external drive partitions are elided):# --- Just after reboot ---$ df -h     Filesystem      Size  Used Avail Use% Mounted on/dev/sda1       9.8G  7.3G  2.0G  80% /none            4.0K     0  4.0K   0% /sys/fs/cgroupudev            428M  292K  428M   1% /devtmpfs            88M  1.3M   87M   2% /runnone            5.0M     0  5.0M   0% /run/locknone            437M  288K  437M   1% /run/shmnone            100M   12K  100M   1% /run/user$ sudo du -x   -d1 -h /186M    /opt512M    /var11M /sbin556K    /root1.3G    /home613M    /lib8.0K    /media4.6G    /usr16K /lost+found111M    /boot39M /etc4.0K    /mnt60K /tmp9.1M    /bin4.0K    /srv7.3G    /            # <-- note this# --- After some time ---$ df -hFilesystem      Size  Used Avail Use% Mounted on/dev/sda1       9.8G  9.1G  199M  98% /none            4.0K     0  4.0K   0% /sys/fs/cgroupudev            428M  292K  428M   1% /devtmpfs            88M  1.3M   87M   2% /runnone            5.0M     0  5.0M   0% /run/locknone            437M   27M  411M   7% /run/shmnone            100M   28K  100M   1% /run/user$  sudo du -x   -d1 -h /186M    /opt511M    /var11M /sbin556K    /root1.4G    /home613M    /lib8.0K    /media4.6G    /usr16K /lost+found111M    /boot39M /etc4.0K    /mnt520K    /tmp9.1M    /bin4.0K    /srv7.3G    /              # <-- note this(Note: I use hibernation.  After the hibernation, the usage stays the same, and after reboot, it resets to 80%.)How do I track what eats the space?I've read this question.  I'm still in the dark.  How do I find out which program is responsible for this behavior?After edit: found it.  The space is claimed by the kernel log, which is seen by dmesg.  It fills up because my machine generates errors at the rate 5 a second.  (It's related to this bug.)  Let the future readers with a similar problem - slowly-filling disk space unseen by du - not forget to try dmesg in searching for the cause.
What's eating my disk space?
linux mint;disk usage