See inline. 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. > I think for resilience you want to go for more budget. I will say, since virtualizing my environment fully I have had 0 unscheduled downtimes for any service, whereas before I had servers I had to reboot more frequently than the patch windows. > > 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 would get two boxes, and two Windows Enterprise licenses, which gives you four guests per machine. It gives you room to grow, and it gives some alternatives if a box craps out on you. Your windows licensing costs will be about the same, but the hardware cost will go up a bit, but you have a measure of redundancy. > > 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. > It's easy to say that, but being able to bring up a guest on another machine because the host crapped out is really nice. There are some licensing implications involved in bringing up a guest on a different host when using Enterprise licenses. Having a SAN, I wouldn't go any other way. The SAN saves me tons of time, and usually it's when I most need to save it, here's my example. I had a host develop a bad disk. The only thing that the disk was doing in the host was booting the host with ESXi, and holding some disk images of software ISOs. I'm paranoid about putting in a disk in a hot-swap RAID array, I know that's what they are for, but I have had a machine lock up on me when I've done it before, so I try and minimize the impact of something like that. The day before I switched the disk, I powered down the VM's and moved them over to the other guest. Took about 3 seconds per guest. I have my guests segregated on the hosts, one is a mission critial host, running all the VMs necessary to do business, and the other one is utility, things like AV, second DC, and other appservers that can withstand a bit of downtime. I then moved all the utility VMs over to the other host (during business hours!). Only one person noticed, because of our OCR app being down. > > 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? > You should be considering and planning an Exchange 2010 migration, if you aren't already. Exchange 2003 can hit disks hard. You could put a vhd on its own disk/array, of course. Exchange 2010 has something like a 95% reduction in iops requirements. I'm saying that from memory, so I might be talking out of my hat, but it was a considerably large percantage. > > 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. > My SBS 2003, which is about to go away, gets 3.5 GB now, and only has 1 processor allocated to it. It does fine, some occasional slowness due to disk IOPS, but that's usually when I'm rebuilding an OST file or something. > > > > > 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 > ~ 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
