Was trying find ways to optimize KVM installs Centos 6.3 or Ubuntu 12.04 and could not find any good information except:
1) modify /boot/grub/menu.lst or /boot/grub/grub.cfg
2) use Virtio Drivers
3) fix Swap Partition
swapoff /dev/vda2
mkswap /dev/vda2
swapon /dev/vda2
4) improve I/O performance
echo 0 > /sys/block/vda/queue/rotational
echo 0 > /sys/block/vda/queue/rq_affinity
echo noop > /sys/block/vda/queue/scheduler
echo "echo 0 > /sys/block/vda/queue/rotational" >> /etc/rc.local
echo "echo 0 > /sys/block/vda/queue/rq_affinity" >> /etc/rc.local
echo "echo noop > /sys/block/vda/queue/scheduler" >> /etc/rc.local
echo 'vm.swappiness=5' >> /etc/sysctl.conf
echo 'vm.vfs_cache_pressure=50' >> /etc/sysctl.conf
sysctl -p
5) mount partition with noatime.
vi /etc/fstab
any other links, tips or ideas?
Ramnode seems to have a well done guide although its geared towards SSDs
https://clientarea.ramnode.com/knowledgebase.php?action=displayarticle&id=44