core-dumping over NFS

Don Lewis truckman at
Mon Jan 12 13:12:36 PST 2004

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.

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