Subject: Re: UVM/other problems for desktop users in current?
To: John Franklin <>
From: Jukka Marin <>
List: current-users
Date: 12/19/2002 22:50:53
On Wed, Dec 18, 2002 at 10:14:27AM -0500, John Franklin wrote:
> > The poor machine can't even handle one CVS operation without failing to
> > serve files over NFS.  CPU usage on the server is less than 20% and
> > there's over 300 MB of RAM available.
> options BUFCACHE <30-50> on the server will clean that up.  BUFCACHE, if
> unmodified, is 5% of your memory.  It's used for both NFS network
> buffers and fs metadata buffers.  For NFS servers 5% is grossly
> inadequate.  Watch systat bufcache (NFS buffers are charged to the root fs.)

Sure enough, 99% of buffers were allocated by root.  But, after setting

options        BUFCACHE=30

I could no longer boot:

cpu0: AMD Athlon Model 4 (Thunderbird) (686-class), 700.10 MHz
cpu0: I-cache 64 KB 64b/line 2-way, D-cache 64 KB 64b/line 2-way
cpu0: L2 cache 256 KB 64b/line 16-way
cpu0: features 183f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR>
cpu0: features 183f9ff<PGE,MCA,CMOV,FGPAT,PSE36,MMX>
cpu0: features 183f9ff<FXSR>
total memory = 511 MB
panic: cpu_startup: cannot allocate VM for buffers

Not so serious, I had my old kernel in root, but the machine is headless
in another room and I haven't got a serial cable wired to the console
port, so I had to carry the computer here to see what was wrong..

So, _how_ do I make it allocate more buffers when BUFCACHE=30 causes a