Nasty interactions between kernel timekeeping and NFS in 2.0.x

Nigel Metheringham (
Mon, 26 Jan 1998 13:34:41 +0000

We have a set of 5 SPARC/20 based systems running (basically) Red Hat 4.2
using either RH 2.0.30 (ie with RH patches + additional security patches)
or 2.0.33 near vanilla kernels.

Three machines are doing serious amounts of NFS work as clients. The
other 2 are news boxes (lots of SCSI disk, no NFS).

The 3 NFS clients lose time dramatically, even when running xntpd (5.90).
The time loss appears uncorrectable - if the tick is adjusted in line with
the daily time slippage, the system still loses time.

The 2 non-NFS boxes keep within 100ms (not good, but SPARCs always did
have crap time keeping performance).

Both sets of boxes are slaving to the same set of timeservers.

Is there some nasty interaction between the 2.0.x NFS client?
Has anyone an idea where this is happening and can it be fixed?


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