Subject: iostat and df -k mismatch

[Tom Greaser]

can you do a iostat -a ? 
what ver of sysstat do you have installed ? 
 rpm -qa | grep sysstat 
 
on my rh3 box its sysstat-5.0.5-5.rhel3 
on fedora 4 its sysstat-5.0.5-9.fc 
 
that might be your problem.. to old of a version