Odd daily run output

[Jimmie James]

[23:38:01]  jimmie at fortytwo <143> [0] ~>uname -a
FreeBSD fortytwo.zapto.org 6.1-PRERELEASE FreeBSD 6.1-PRERELEASE #0:
Thu Feb  2 08:01:49 EST 2006    
root at fortytwo.zapto.org:/usr/obj/usr/src/sys/FORTYTWO  i386

Date: Tue, 14 Feb 2006 03:04:29 -0500 (EST)
Subject: fortytwo.zapto.org daily run output
Disk status:
Filesystem  1K-blocks     Used    Avail Capacity  Mounted on
/dev/ad0s1a    253678    53922   179462    23%    /
devfs               1        1        0   100%    /dev
/dev/ad0s1e    253678    -1358   234742    -1%    /tmp
/dev/ad0s1f 111776478 17198238 85636122    17%    /usr
/dev/ad0s1d    253678    25808   207576    11%    /var
procfs              4        4        0   100%    /proc
fdescfs             1        1        0   100%    /dev/fd

[23:38:02]  jimmie at fortytwo <144> [0] ~>mount
/dev/ad0s1a on / (ufs, local, acls)
devfs on /dev (devfs, local)
/dev/ad0s1e on /tmp (ufs, local, soft-updates, acls)
/dev/ad0s1f on /usr (ufs, local, soft-updates, acls)
/dev/ad0s1d on /var (ufs, local, soft-updates, acls)
procfs on /proc (procfs, local)
fdescfs on /dev/fd (fdescfs)

[22:39:32]  jimmie at fortytwo <120> [0] ~#du -sh /tmp/
 16K    /tmp/


I know there's 8% reserved for softupdates, but how is it possible
that there's _extra_ space on /tmp ?  What am I missing?  This is the
first time I've seen this.

The only issue I've had was a hardlockup (not reproducable, nothing in
logs) doing a kldunload msdosfs.ko the other day.