I second the recommendations to get multiple boxes. If you have a hardware problem, having backups is good, but doesn't help you get running again, and you'll have a whole lot that is not running.
Except for the smallest scenarios, I don't recommend a single VM host. (I now have two at home, managing a total of 8 VMs) SCSI is fine, but SATA will be good enough for the load you are suggesting, too. Actually, I would seriously make the case for a SAN now (start with something like a QNAP). Then you can keep the servers as SCSI, but use SATA more cost effectively in the SAN. The reason to go with the SAN now, is that you're putting a lot of storage in one place, and if you don't do it now, you'll have even less impetus to do it when you add the very next service or function. Plus it gives you WAY more flexibility than not having one. Don't overdo growth potential. Plan for the next 3 years, but not much more than that. Things change too much to be planning 5 years out. RAM is where you will want to put the most effort, as many have stated. You will feel the impact the most there. CPU sizing is not going to pose as much of a problem. If you get a Dual socket, quad core or six-core system, you'll be fine for the suggested workloads, even on a single machine. It's the RAM that will make the most difference. 1GB of RAM for VMs should work just fine in your scenario, as far as what I've read in your description. Really, really try to do the SAN thing now. Seriously. * * *ASB* *http://XeeMe.com/AndrewBaker* *Harnessing the Advantages of Technology for the SMB market… * On Fri, Dec 2, 2011 at 1:07 PM, Ben Scott <[email protected]> wrote: > Sorry to interrupt the cell phone talk, but I've got a question > about NT system administration. ;-) > > I'd appreciate any input people have on this. Thoughts, > suggestions, recommendations, dopeslaps, etc. Pointers to references, > or FMs to R, are also welcome. > > SUMMARY > > * Spec'ing a server for small business virtualization > * Best hard drive config? > * Eight fast mid-sized disks in one big RAID 10? > * Larger slower mirrored disks, but some dedicated to workloads? > * Unsure as to RAM and CPU sizing > > BACKGROUND > > The Powers That Be here at %WORK% have finally agreed to let me > upgrade our server infrastructure (and there was much rejoicing). > We're a small shop, basically just two servers, with most everything > running on a single server. DC, file, print, Exchange, apps, etc., > all on the one box. Obviously far from ideal, but it wasn't > cost-effective to do anything else before. With virtualization now > being in our reach, my goal is to split that into dedicated VMs, and > move everything on to a single physical box. > > I've not found much capacity planning guidance for small businesses > who want to do virtualization on a single server. All the guides seem > to assume 1000s of users, and help one figure out how many servers to > buy for one's load. I'm trying to figure out how much of a server to > buy, for the varied VMs I want to put on it. > > CURRENT ENVIRONMENT > > * Single physical site, single domain, single AD site > * 100 MB NTDS, 285 MB SYSVOL > * 85 named users, plus a dozen or so shared role accounts > * 120 CALed PCs > * 370 GB plain old files on the file server > * 150 GB Exchange information store > * 130 GB other stuff (OS overhead, server software, OS images, WSUS, etc.) > * 25 network printers > * Win 2000 Server (I know, I know); Exchange 2003 > > MY PLAN SO FAR > > We're a Dell shop, so PowerEdge T710. Eight disk bays. Two CPU sockets. > > Win 2008 R2 Datacenter. Gotta love the unlimited VMs. > > Hyper-V, simple because it makes the support question less complicated. > > Budget isn't set in stone, but I'm shooting for the 8 - 12 kilobuck > range, including service contract, not including software. Obviously > we don't want to spend more than we have to, but if something is > cost-justified I can argue to get it. > > At least five VMs: DC/DHCP/DNS. Exchange. File server. Print > server (ill-behaved print drivers). And one catch-all -- WSUS, BES, > anti-virus server, license servers, a few tiny vendor-app databases. > Maybe split that last one up a bit more, maybe not. > > I think a SAN would be overkill for us right now. One nice thing > about virtualization is that we can easily migrate the VHDs to a SAN > when get to that point. > > DISK CONFIGURATION > > Traditional wisdom was to use dedicated spindle sets for things like > Exchange. Your dedicated Exchange server would have a small mirror > for OS and software, a small mirror for the transaction logs, and > however much you needed for the Information Store. Virtualization > makes the question more complicated. > > I could get eight mid-sized 15 KRPM disks, and put them in RAID 10 > (stripe of mirrors). Have most of it be a giant partition on the > host, containing all the VHDs. > > Or I could get larger, 7.2 KRPM disks, put them in mirrored pairs, > and dedicate mirrors to workloads. One mirror set for the Exchange > IS, another for the logs, a third for plain old files, and a fourth > for everything else. Or some variation on that theme. > > Thoughts on this? > > RAM AND CPU SIZING > > For such a small environment, am I okay oversubscribing the physical > cores/hyperthreads? For example, if I get a single six core processor > (leaving the second socket open for future expansion), will that be > okay? Does Exchange have to have multiple dedicated cores to run > well? > > Likewise, how much RAM do I really need to give the single-purpose > VMs? I'm thinking 1 GB for the print server. Will the DC be okay > with 1 GB? I'm thinking the more RAM I can give Exchange and the file > server, the better, so there's a trade-off here. > > > > > Thanks for reading. :) > > -- Ben > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to [email protected] with the body: unsubscribe ntsysadmin
