Initial thoughts: Spend some time logging your IOPS so you know what you need to support.
Don't skimp on RAM - that is where you will usually start to see a bottleneck long before you do CPU and disk (assuming you know what IOPS you need and spec accordingly). Ideally, buy two boxes, with one box all your eggs are in one basket, though accepted you're not going to be much worse off than you are now. Don't rule out SAN storage. People think SAN and think expensive hardware - there are a number of low cost (relative) software SANs that let you take DAS storage and pool it and cluster it. Backup - don't overlook it. Windows - look at licensing using Enterprise which gives you 4 VM licenses, DataCenter is cool and good VFM but you need to license a minimum of 2 processor licenses per physical box. Exchange 2003 - ignoring all the support and other issues around that, Exchange 2010 is a magnitude of performance better on disk IO than 2003, I would look at upgrading that as soon as you're able to. Paul ________________________________________ From: Ben Scott [[email protected]] Sent: 02 December 2011 6:07 PM To: NT System Admin Issues Subject: Virtualization - Sizing, hard disk config 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 -- MIRA Ltd Watling Street, Nuneaton, Warwickshire, CV10 0TU, England Registered in England and Wales No. 402570 VAT Registration GB 100 1464 84 The contents of this e-mail are confidential and are solely for the use of the intended recipient. If you receive this e-mail in error, please delete it and notify us either by e-mail, telephone or fax. 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