df -k reports inaccurate values for large NFS filesystems

[Paul Robertson]

System running RHES 3.0 on i386. Using automount to mount 4TB NFS
filesystem on a NetApp filer, but "df -k" reports the filesystem size as
about 256GB:

da1253:/boot>df -k /nc/1
Filesystem           1K-blocks      Used Available Use% Mounted on
nusna05-nas:/vol/extract02/nc/1
                     256659356 147320120 109339236  58% /nc/1

When we pass the 100% full point, we see the following:

da1253:/boot>df -k /nc/1
Filesystem           1K-blocks      Used  Available Use% Mounted on
nusna05-fe:/vol/extract02/nc/1
                     256659356 -9223372035005238872 2106196292 101% /nc/1

Clearly a bug, but it's odd that this problem doesn't seem to occur
with RHAS2.1, running older df and older kernel. 

It semes to be just a 'df' reporting error, in that we can fill up the
filesystem well past the 100% point, but some scripts depend on being
able to assess which filesystem has the most available space, and
they're breaking now. What can we do to fix this?

Cheers,

Paul

P.S. System detail follows:

 da1200:~>uname -a
 Linux da1200.nus.ironmountain.com 2.4.21-15.ELsmp #1 SMP Thu Apr 22 00:18:24 EDT 2004 i686 i686 i386 GNU/Linux

 da1200:~>cat /etc/redhat-release
 Red Hat Enterprise Linux ES release 3 (Taroon Update 2)

 da1200:~>rpm -qf `which df`
 coreutils-4.5.3-26

-- 
Paul Robertson
Email: probertson at unixway.com
Phone: 617-784-1575
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