No particular reason, other than I use the same directory to back up the windows machines as well. I'm sure that the OpenSolaris NFS implementation would be fast or faster than CIFS. If you're using Linux or BSD I've heard that NFS has some occasional hiccups (stale lock issues) and performance problems. Take the previous sentence as pure gossip as I haven't seen or done any testing to prove/disprove it.

You're right on the button. I created a sparse file for each machine image using diskutil so I could fix maximum size (I'd hate it to take over my entire 2.5 TB pool). The trick is to figure out the name that each machine wants, but worse comes to worse, you cancel it quick on the first sync if it's wrong and then rename the file and start it again.

Then I used the native CIFS service that comes with OpenSolaris for the connection. I started with Samba, but the native CIFS service had 1000X better throughput.

There is an option that enables mounting "foreign" disks for time machine. This may explain it better:

http://www.macosxhints.com/article.php?story=20080420211034137

Well, I've been using ZFS for several years on several different machines with mixes of mirrored and RAID-Z configurations. Since that time, I've never lost one bit of data. It has survived power-supply failures, lightning strikes that fried the motherboard, flaky I/O cards, and human error. I understand that the implementation on Mac OS/X may be buggy, but it's not inherent to ZFS. I've several Macs doing time-machine to networked ZFS drives. It's definitely the filesystem I'd like to have everywhere.

Many high security establishments, both government and commercial, realize that they can't stop technology without serious concessions. What some do are to put a special tamper-proof tag over the camera. Then they just inspect the tag when you exit and, if tampered, confiscate the device until it can be validated.

I had to work on a bug on some critical software on a small military plane. I had to drive through a bad snowstorm with the car full of equipment for a full day to get to the plane. The plane came in late and ended up losing it's hanger space. I was stuck on a metal chair outside the plane on the tarmac, in sub-freezing weather, using my computer for warmth. The power was being powered by a diesel generator that made thinking near impossible. I was told that, if I didn't have it fixed by the end of the day, I would have to fix it on the way to their assignment... in Bosnia! I worked late in the evening, freezing and without breaks, but finally got things straightened out. I hope to never go through something like that again.

The CPU should support VT extensions and have plenty of RAM. If you figure 1-2 GB of RAM for each VM running concurrently, you should have a good estimate of what you need. A good OS platform to use is OpenSolaris because it's open source. In addition, it supports Xen, Zones, and other virtualization approaches. With OpenSolaris's Crossbow (network virtualization) you can not only have a testbed for VMs, but you can stress-test your VMs under different network characteristics (long latencies, etc.). Throw in Dtrace to track down issues and you have a real winner.

And ZFS has native support for SSD as L2ARC. http://www.c0t0d0s0.org/media/presentations/ssd.pdf I have nothing but praise for ZFS. Simple to manage, reliable, fast. With native CIFS instead of User file system Samba, I've seen orders of magnitude performance from windows machines when doing networked file access. Gary

As for Samba performance... I have an OpenSolaris server which I use with a 2.5 TB disk stack in a Raid-5z configuration as a NAS for my SOHO setup. I set it up to use as Mac OS/X time-machine server for my Mac machines. With Samba, the initial backup took about 5 hours and consumed 1 of my two CPUs. I switched over to the native CIFS server in OpenSolaris and tried it from scratch again. This time it took under 2 hours and consumed less than 1% total CPU. I had similar experiences when I backed up my Windows machines. Sun still has the fastest NFS stack if that's the way you want to go as well. But, I typically use dirvish (rsync based) to back up my Unix/Linux machines nightly to the server. In 3 years of heavy use, I've never had a single hiccup.