free space reported incorrectly

[Colin Farley]

I'm running FreeBSD 4.10-RELEASE-p16 on a couple of production mail
relays/web servers.  Today I noticed that one had a lot more space in /var
used.  I figured that a log was growing and started to investigate.  After
running du -h /var and seeing it come up with a total usage much less than
what df -h reports I decided to run fsck /var.  This is the output I get:

** /dev/da1s1f (NO WRITE)
** Last Mounted on /var
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
UNREF FILE I=538020  OWNER=vscan MODE=100640
SIZE=251844 MTIME=Dec  5 14:27 2005
CLEAR? no

UNREF FILE I=806417  OWNER=clamav MODE=100640
SIZE=281460 MTIME=Dec 14 15:49 2005
CLEAR? no

UNREF FILE I=806441  OWNER=www MODE=100644
SIZE=183241 MTIME=Dec 14 04:34 2005
CLEAR? no

UNREF FILE I=806446  OWNER=clamav MODE=100640
SIZE=352331 MTIME=Dec 14 15:25 2005
CLEAR? no

UNREF FILE I=806465  OWNER=www MODE=100644
SIZE=39865 MTIME=Dec 14 01:29 2005
CLEAR? no

UNREF FILE I=806467  OWNER=www MODE=100644
SIZE=132 MTIME=Oct 26 00:01 2005
CLEAR? no

UNREF FILE I=806484  OWNER=www MODE=100644
SIZE=10908 MTIME=Dec 14 01:29 2005
CLEAR? no

UNREF FILE I=806487  OWNER=www MODE=100644
SIZE=223963235 MTIME=Dec 14 16:01 2005
CLEAR? no

UNREF FILE I=806501  OWNER=www MODE=100644
SIZE=132 MTIME=Oct 26 00:01 2005
CLEAR? no

UNREF FILE I=806509  OWNER=root MODE=100644
SIZE=663256384 MTIME=Dec 14 16:01 2005
CLEAR? no

UNREF FILE I=806516  OWNER=www MODE=100644
SIZE=132 MTIME=Oct 26 00:01 2005
CLEAR? no

UNREF FILE I=806523  OWNER=www MODE=100644
SIZE=132 MTIME=Oct 26 00:01 2005
CLEAR? no

** Phase 5 - Check Cyl groups
SUMMARY INFORMATION BAD
SALVAGE? no

BLK(S) MISSING IN BIT MAPS
SALVAGE? no

3954 files, 479350 used, 4701227 free (2355 frags, 587359 blocks, 0.0%
fragmentation)

I see there are a couple of large files there that seem to have some
problems.  Can anyone explain what is going on and maybe point me in the
direction of a good document on fsck and common problems?

Thanks,
Colin