Freebsd 6 and nfsstats counters

[krad]

Hi,

I have a bunch of old freebsd servers I want to collect nfs stats from. The
problem is a lots of the counters have wrapped around. On other Freebsd 7+
machines I take care of this be a weekly cron of  "nfsstat -c -z". The z
option isnt available in freebsd 6, and I cant see a direct sysctl OID i
can reset. Has anyone encountered this issue in the past and found a fix.
I'd rather avoid having to alter the scripts to cater for negative numbers.

k