> I'm not a kernel-tuning expert, but it sounds like your work load is
> heavily file-I/O oriented, so you might want to try patching the
> kernel variable:
> 
> 	gdb -k --write /netbsd
> 	set bufpages = 2048
> 
> Alternatively, you can set this using a config option:
> 
> 	option BUFPAGES=2048		# 16MB of buffers!

hmmm, not really successful.

this causes the following fatal error (comes up just after "real mem = ")

kmem_suballoc: bad status return of 3

note that i am using a serial console, and when i get the debug prompt,
the system is non-responsive.  i guess i should check my parity etc settings.
what settings do you have on your serial consoles?
(also, i have several suns on a serial switch, and if i switch to a different
machine, the netbsd machine hangs.  this is different from sunos, in that the
sunos machines would drop to monitor mode when i switched _back_ to them).

this happens when i both do the gdb thing, or when i build a kernel fresh
with "option BUFPAGES=2048".

here is the config file i am using:

#	$NetBSD: TUATARA,v 1.24.2.1 1995/11/18 07:15:57 gwr Exp $

#
# TUATARA Sun3 (3/50, 3/60, 3/110, 3/160, 3/260)
# Supports root on: ie0, le0, sd*, ...
#

include "std.sun3"

# Machines to be supported by this kernel
#options		GENERIC
#options 	FPU_EMULATE		# not needed for 3/200
options 	HAVECACHE		# Sun3/260 VAC
#options		BUFPAGES=2048	# 16MB of buffers!

# Needs to be set per system.  i.e change these as you see fit
maxusers	20

# Standard system options
options		SWAPPAGER, VNODEPAGER, DEVPAGER	# paging
#options		KTRACE				# system call tracing support
#makeoptions	DEBUG="-g"			# symbols for kgdb + nm
options 	DDB

# Filesystem options
options 	NFSSERVER			# nfs server support
options 	NFSCLIENT			# nfs client support
options 	FFS				# ufs file system
#
options		CD9660		# ISO 9660 + Rock Ridge file system
options 	FDESC		# /dev/fd/*
options		FIFO		# FIFOs; RECOMMENDED
options		KERNFS		# /kern
options		NULLFS		# loopback file system
options 	PROCFS		# /proc
options 	UNION		# union file system

# Networking options
options		INET				# IP prototol stack support
# XXX - Work-around for root on slow SunOS/Sun3 servers (sigh...)
options 	NFS_BOOT_RWSIZE=1024

# Compatability options
options 	COMPAT_SUNOS	# can run SunOS 4.1.1 executables
options 	COMPAT_09	# NetBSD 0.9,
options 	COMPAT_10	# NetBSD 1.0,
options 	COMPAT_43	# and 4.3BSD
options 	TCP_COMPAT_42	# TCP bug compatibility with 4.2BSD

# Sun3-specific debugging options
#options 	CONTEXT_DEBUG
#options 	PMAP_DEBUG
#options 	VMFAULT_TRACE
#options 	SYSCALL_DEBUG
#options 	EXEC_DEBUG
options 	DIAGNOSTIC
options 	SCSIDEBUG

config		netbsd	root on sd0 swap on sd0 and sd1 and sd2 and sd3

#
# Network devices
#

# Intel Ethernet (onboard, or VME)
ie0 at obio0 addr ? level ?
ie1 at vmes0 addr 0xffe88000 level 3 vect 0x75

# Lance Ethernet (only onboard)
#le0 at obio0 addr ? level ?

#
# Disk and tape devices
#

# Sun3 "si" SCSI controller (NCR 5380)
ncr_si0 at obio0 addr ? level ?
ncr_si0 at vmes0 addr 0xff200000 level 2 vect 0x40
ncr_si1 at vmes0 addr 0xff204000 level 2 vect 0x41

# Xylogics 7053 controllers
# xdc0 at vmel0 addr 0xffffee80 level 2 vect 0x44
# xdc1 at vmel0 addr 0xffffee90 level 2 vect 0x45
# xd* at xdc? drive ?

# Xylogics 450/451 controllers
# xyc0 at vmes0 addr 0xffffee40 level 2 vect 0x48
# xyc1 at vmes0 addr 0xffffee48 level 2 vect 0x49
# xy* at xyc? drive ?

# Xylogics 472 tape controllers?

#
# Frame buffer devices
#

# The default cgfour address depends on the machine:
# 3/60: obio 0xFF200000 .. 0xFF9fffff
# 3/110: different? (not tested)
#cgfour0 at obmem0 addr ?

# 3/60 P4 accelerated 8-bit color frame buffer
# cgsix0 at obmem0 addr ?

# 3/60 P4 24-bit color frame buffer
# cgeight0 at obmem0 addr ?

# The default bwtwo address depends on the machine:
# 3/50: obio   0x100000
# else: obio 0xff000000
#bwtwo0 at obmem0 addr ?
# 3/60 P4 color frame buffer overlay plane, or P4 monochrome frame buffer
#bwtwo1 at obmem0 addr 0xff300000
# 3/60 plug-in color frame buffer overlay plane
#bwtwo1 at obmem0 addr 0xff400000

# Sun-3 color board, or CG5 8-bit VME frame buffer.
#cgtwo0 at vmes0 addr 0xff400000 level 4 vect 0xA8

# Support for the CG9 24-bit VME frame buffer.
# cgnine0 at vmel0 addr 0x08000000

#
# SCSI infrastructure
#
scsibus* at scsi?

# Sun compatible scsi device mappings
sd0 at scsibus? target 0 lun 0
sd1 at scsibus? target 1 lun 0
sd2 at scsibus? target 2 lun 0
sd3 at scsibus? target 3 lun 0
#sd4 at scsibus? target 4 lun 0
sd5 at scsibus? target 5 lun 0
#sd6 at scsibus? target 6 lun 0
sd* at scsibus? target ? lun ?

st0 at scsibus? target 4 lun 0
st* at scsibus? target ? lun ?

cd0 at scsibus? target 6 lun 0
cd* at scsibus? target ? lun ?

#ch* at scsibus? target ? lun ?


# RAM-disk drivers
#rd0 at mainbus?
#rd1 at mainbus?

# Misc.
pseudo-device	loop	1		# network loopback
pseudo-device	bpfilter 8		# packet filter
#pseudo-device	sl	2		# CSLIP
#pseudo-device	ppp	2		# PPP
#pseudo-device	tun	2		# network tunneling over tty

pseudo-device	pty	32		# pseudo-terminals
#pseudo-device	vnd	4		# paging to files

-- 
[ Jim Mercer   Reptilian Research  merce@iguana.reptiles.org  +1 416 410-5633 ]
[  when you eat hot chiles you should follow them with some ice cream.  Then, ]
[  when you're sitting on the toilet the next day and the burn commences, you ]
[  can holler "Come onnnnnn, ice cream!"-- from the chile-heads mailing list  ]