Advice for CPU/Mobo for Citrix Xen Server

[Flapjack]

Hey all. I recently built a baremetal Citrix Xen server as a test bed for virtualizing my domain. I'm getting ready to migrate my family domain from Win2k3 to Win2k8 now that I finally got some licensing for it. My current network sports a Win2k3-x64 server running Exchange 2007, a Win2k3-x86 server acting as the only DC, and a old Dell WinXP box running NoSpamToday for mail filtering.

The migration is going to be tough, as I'm changing the domain name altogether. I did a sloppy job planning the domain in the first place. While it works, I'd have a lot of bandaids in place. Since I'm migrating to to 2k8, I'd like to take the opportunity to setup my domain and DNS perfectly. It'll involve buying new SSL certs, but it'll be worth it... to me, at least.

Basically, I'd like an AMD quad-core (preferably a Phenom II). I don't think there's a need for a Opteron. It seems like the Phenom has much better technology and would work better for this application. Plus, the Opteron mobos are outrageously priced.

For the motherboard, I'd like something that could do RAID5 (onboard) and run with 16GB of RAM. I already have two 1.5TB SATA drives, I would just need another for a 3.0GB RAID5 array with parity.

Really, I guess the advice I need most is for the motherboard. There are a lot out there, and I'm simply lost. I think what I need is a 790GX (since I don't need a fancy video card), but which would have RAID5 and good stability? I don't necessarily need the fastest motherboard out there, but if I can get it for a reasonable price, why not?

Currently, I'm running one Win2k3 DC, one Win2k3-x86 Exch2007 mail server, and crappy little spam filtering box. What I would like this setup to be able to handle is two Win2k8 DCs, one Win2k3 file server, and one WinXP machine for spam filtering.

Oh yeah, my Active Directory consists of maybe 10 users... only half of which use email.

Any recommendations? I don't have a whole ton of jack to spend, either...

 

[sabregen]

almost every motherboard (sparing workstation and server board from the likes of Supermicro and Tyan, with real RAID controllers) will not support RAID-5. They'll usually do RAID-0/1/10. Some might do RAID-5, but they lack a true hardware XoR engine, battery backup, and additional cache. RAID-5 is a performance killer, even on decent cards. Given the list of VMs you're planning on running, and the number, I would suggest not doing RAID-5 on the disks you currently are planning on using. I would personally throw more spindles at the idea than you currently have, and run JBOD or RAID-0. The recommendation is for max of 2 VMs per spindle, and RAID-5 will also incur a major performance hit. Plus, if the array has to recalculate parity, the larger the disk, the higher the chance for data loss, and the longer the rebuild times.

My honest recommendation would be to get whatever motherboard you want, and not use any of it's on board RAID functionality, unless you can handle just having RAID-0 or RAID-1. Even then, a decent starter RAID controller would be a good idea. A Dell Perc5/i with SFF8484 cables, and adding the additional cache and BBU later would be a good start. They can be found regularly on eBay under $150 without cache and BBU. In addition to this, I would get a few used WD 320AAKS SATA drives, or some cheap 36GB SAS 10k drives (or whatever you can find that's fast and cheap).

RAID-5 on 3 disks sucks, and the larger the disks are, the worse it sucks. I should however, qualify this statement and say that we're talking about onboard or desktop RAID controllers, on 3x SATA 7200RPM disks. Our 3x RAID-5 sets at work are just fine, but they're 300GB 15k RPM 4Gb/sec FC disks on an enterprise level FC RAID controller.

 

[Flapjack]

So you're recommending I go with RAID0 or RAID1? I guess if I go RAID0, I can just backup the images occasionally and be fine. I guess I'll just do that. I'll get a large USB drive that I can plug in and do backups when needed.

That being said, what is a good CPU for the amount of VMs I'm planning on running? Would a Phenom II 920 be a good choice?