/root is full

[Haines Brown <haines@histomat.net>]

This is such a classic problem that I hesitate to raise the
question. The df below shows that the usual suspects for root partition
being full are broken out. The / partition is 500 Mb. In the past I have
only used about 50 Mb.

  # df
  Filesystem             1K-blocks     Used Available Use% Mounted on
  rootfs                    474440   474440         0 100% /
  udev                       10240        0     10240   0% /dev
  tmpfs                     830924     1572    829352   1% /run
  /dev/disk/by-uuid/d3a2... 474440   474440         0 100% /
  /dev/sdb5               48062440 10165348  35455616  23% /home
  /dev/sdb6               28834716  4261020  23108972  16% /usr
  /dev/sdb7               38448276  2372784  34122392   7% /var
  /dev/sdb8               19228276   994260  17257268   6% /tmp
  /dev/sdb9               38448276 12808004  23687172  36% /usr/local
  /dev/sdb12              96124904 11577356  79664596  13% /info
  /dev/sdb13             192243928 58177436 124300984  32% /storage

I verified that root is indeed full by trying to copy a file to it.

I ran:
  # find / -type f -size +100M -exec ls -lh {} \; | awk '{ print $9 ": " $5 }'

All files that were over 100 Mb were located in broken out directories
except this:

  /sys/devices/pci0000:00/0000:00:06.0/0000:01:00.0/resource1: 256M
  /sys/devices/pci0000:00/0000:00:06.0/0000:01:00.0/resource1_wc: 256M

  This is peculiar and a suspicious size. So I go its directory to
  verify:

    # ls -la | grep resource1
    -rw------- 1 root root 268435456 Jul 29 08:13 resource1
    -rw------- 1 root root 268435456 Jul 29 08:13 resource1_wc

  but:

    # file resource1
    resource1: ERROR: cannot read `resource1' (Input/output error)

I ran $ du -h on all the directories mounted on / and not broken out,
and their total came to 350 Mb. This strikes me as big, but still is not
greater than the partition size.

Haines