Comment 29 for bug 1295732

Some improvements in the weekend:

- Small improvements when the bm nodes are configured with 4 CPUs instead of 2
- Small improvements when the vm are configured with cpu=host-passthroug
- Huge improvement in the undercloud boot time when seed is configured with 4CPUs and 8GB RAM
- Using tmpfs for the images directory (/var/lib/libvirt/images) makes some improvement when booting the seed, but fails with the others (maybe RAM exhaustion)

Next steps:
- Use tmpfs again, but configuring the nodes with 4GB to avoid RAM exhaustion
- Configure using memory huge pages
- CPU pinning
- Try with raw partitions vs qcow2
- Disable barriers in ext4
- Caching modes none and unsafe
- I/O schedulers

Must look:
- Confirm that overcloud boot times when performing a full deployment (not using -c) is actually >50% improvements than any other options and why!

Best time: (ubuntu end user)
[2014-03-30 13:30:34] Total runtime: 2783 s
[2014-03-30 13:30:34] ramdisk : 105 s
[2014-03-30 13:30:34] seed : 544 s
[2014-03-30 13:30:34] undercloud : 684 s
[2014-03-30 13:30:34] overcloud : 1422 s

-c (cirros)
[2014-03-28 16:57:18] Total runtime: 1088 s
[2014-03-28 16:57:18] ramdisk : 0 s
[2014-03-28 16:57:18] seed : 248 s
[2014-03-28 16:57:18] undercloud :277 s
[2014-03-28 16:57:18] overcloud : 555 s

NODE_CPU=4 NODE_MEM=8192 NODE_DISK=30 NODE_ARCH=amd64
seed=> NODE_CPU=4 NODE_MEM=8192 NODE_ARCH=amd64
<cpu mode='host-passthrough'/> in vm.xml
Using cirros fo rend user image with -c
virtio