core-dumping over NFS

[Doug White]

On Mon, 12 Jan 2004, Don Lewis wrote:

> >> On 12 Jan, Mikhail Teterin wrote:
> >>
> >> > 	. 5.2-CURRENT (Dec 14) server, RedHat-9 client:
> >> > 		core is created properly, but sometimes the server goes
> >> > 		into a frenzy with the sys-component (bufdaemon) taking
> >> > 		up the entire 100% of the CPU-time (P4 at 2GHz); it only
> >> > 		writes @4Mb/s (~14% of the disk's bandwidth) and the
> >> > 		only cure is to restart the /etc/rc.d/nfsd; trying to,
> >> > 		for example, switch from X11 to a textual console, when
> >> > 		this is happening reliably hangs the machine.
> >>
> >> I saw something similar a in the last month when running iozone on a
> >> FreeBSD client with an nfs file system mounted from a FreeBSD server.  I
> >> think this was in the 5.2-BETA timeframe.  The client typically ran out
> >> of CPU first, but the server was not far behind.  This happened in the
> >> tests with the larger file and/or block sizes.  Bufdaemon was typically
> >> the big consumer of CPU.
> >
> > Hm, I can attempt to reproduce this on 5.2-rel or -current. Can you
> > provide the options used to iozone?
>
> I think I used the defaults other than cranking up the max file size go
> 1GB to match the memory size on my server.  It took a long time to run
> the full set of tests ...

OK, I'll tive it a try. NFS between different FreeBSD versions in my
pile-o-machinery have all come up OK, but I'll try against redhat.

-- 
Doug White                    |  FreeBSD: The Power to Serve
dwhite at gumbysoft.com          |  www.FreeBSD.org