/etc/sysctl.conf:

vm.swappiness = 0
vm.overcommit_memory = 1
vm.dirty_background_ratio = 5
vm.dirty_ratio = 10
vm.dirty_expire_centisecs = 1000
dev.rtc.max-user-freq = 1024

example .vmx im using:

#!/usr/bin/vmware
config.version = "8"
virtualHW.version = "4"
scsi0.present = "TRUE"
scsi0.virtualDev = "lsilogic"
memsize = "768"
ide0:0.present = "TRUE"
ide0:0.fileName = "Ubuntu.vmdk"
ide0:0.deviceType = "rawDisk"
ide1:0.present = "FALSE"
ide1:0.fileName = "/root/dist/ubuntu-7.04-server-i386.iso"
ide1:0.deviceType = "cdrom-image"
floppy0.fileName = "/dev/fd0"
Ethernet0.present = "TRUE"
displayName = "isis"
guestOS = "ubuntu"
priority.grabbed = "normal"
priority.ungrabbed = "normal"

floppy0.present = "FALSE"

ide0:0.redo = ""
ethernet0.addressType = "generated"
uuid.location = "56 4d 41 cd 3f 78 ed 06-f0 b9 64 99 ce 17 8d d8"
uuid.bios = "56 4d 41 cd 3f 78 ed 06-f0 b9 64 99 ce 17 8d d8"
ethernet0.generatedAddress = "00:0c:29:17:8d:d8"
ethernet0.generatedAddressOffset = "0"
ethernet0.virtualDev = "e1000"

workingDir = "."
MemTrimRate = "0"
sched.mem.pshare.enable = "FALSE"
MemAllowAutoScaleDown = "FALSE"