Recommendations for virtualisation server

[sidewinder]

Speccing a new server that is intended to virtualise a few older servers, and provide capacity for a few new ones.

 

Looking at a Dell R710, 2x Xeon E5540 2.52Ghz, 24GB 1066Mhz DDR3, and as for drives? Thats the bit Im not sure on

 

For the last few servers I've started buying SATA drives to save money as they provide adaquate performance for a file server. But should I be looking at 10-15K SAS drives for this, or stick with SATA? Capacity is still important, we dont have a SAN, so there needs to be plenty of space, though I'm not planning on running any major file servers or big databases on any VM's, would rather keep them to physical boxes (or would they be ok?)

 

Also is the initial spec too high/not high enough?

 

Its all slight guesswork at the minute, because although I know the 2 servers I want to migrate to it (print/sophos and my PCE server) I dont know what will be needed after that.

I would like to virtualise one DC, as both of ours are out of warranty and could do with replacement. I've seen arguments for and against this, so whats the consensus? I would still keep one on a physical box.

 

Finally, is Hyper-V as good as MS say? I havent got any compatible (spare) hardware to try it out here. And VMware is a bit beyond our budget I think, especially as none of us have much experiance in it

Edited January 19, 2010 by sidewinder

[carnforthhigh]

We recently purchased an R710 with 2x Xeon E5520 2.27GHz and 32GB 1066 DDR3 with Citrix Xenserver embedded. We use a Netgear Readynas 2100 for the storage of the VMs.

 

Runs without a hitch, currently hosting 5 VMs running various tasks; print serving, Sophos, PCE, Helpdesk, MLS.net and various school applications. We would highly recommend this server!

[sidewinder]

cheers

 

So you dont have any performance issues storing the VM's on a NAS device? If thats the case it may well mean I'd be fine with SATA drives

[Guest Guest]

It really depends on how many users etc, but personally id say no to sata and goo with SAS. It also depends on how many, 1 SAS isnt going to perform as well as 8 sata etc.

 

CPU - go for the latest generation you can. If you ever plan to use Pools, live migration etc, you will need similar CPUs so could end up in a situation where you will have to bin your current servers and buy all new ones, which half defeats the point in virtualisation. getting the latest gen means you are more likely to be able to still buy them come upgrade time.

[apaton]

I've used DELL's R700 a number of times for VMware's vSphere ESX, worked perfectly and nice server to work on.

 

SATA or SAS, both will work but if you can afford it go for SAS and a RAID controller.

 

For VMware look at Essentials Plus Edition could be a competitively priced alternative, but your right VMWare is typically more expensive at the highend.

 

Regards

 

Andy

[SYNACK]

You may be able to get away with SATA as long as you RAID them up for greater speed/redundancy. The other thing to look at is the server grade SATA drives like the Seagate ES2 line. They are manufactured for server use and so are much better suited to it while only costing a small bit extra. If I had the choice I would be using SAS though.

 

As to Hyper-V it seems to run fine in my setup. It is suprising what it will run on as I had it going on my laptop with no hassles. Just needs a CPU with virtualisation extentions, other than that it is not fussy.

[sidewinder]

Thanks for the advice guys

 

SAS isnt out of the question, I have a reasonable budget, but there would have to be a trade off in capacity. Then again, even with 4/5 servers its unlikely I'm going to need 4Tb especially as they wont be file servers.

 

Was thinking of going for RAID6 rather than 5 just for some extra protection since if 2 drives failed it could potentially take out multiple machines. Or is that OTT - considering that one of the benefits of virtualisation is portability...could always move VM's to another server as a temporary measure

[tmcd35]

Unless I've missed something here in all this talk of hard drives, you may want to consider a fast NAS or basic iSCSI SAN box rather than a local server RAID. Even if you only have one virtual host to start with but odds on eventually you may want to had a second or third host server, or convert one of your existing servers into a virtual host.

 

Even without live migration and automatic distaster recovery. Storing VM's on shared hard drive space is one of the more useful applications of virtualisation. The ability to restart any virtual server on any virtual host is a real revolution.

 

Edit: I'd personally look at perhaps 74Gb RAID-1 10krpm SATA drives on the server for Windows 2008 R2 + Hyper-V and then perhaps something like the ReadyNAS to store the VM images. In fact that's what I will be doing in the summer but rather than use a Netgear ReadyNAS I have it in mind to build my own NAS box with a HP server and a copy of Windows for SMB file share.

Edited January 19, 2010 by tmcd35

[Guest Guest]

^ Agreed. 4-5 servers with 4+ HDs and RAID cards is a long way to purchasing a SAN. Just remember though that a single SAN becomes your single point of failure for every server you are running.

[SYNACK]

Was thinking of going for RAID6 rather than 5 just for some extra protection since if 2 drives failed it could potentially take out multiple machines. Or is that OTT - considering that one of the benefits of virtualisation is portability...could always move VM's to another server as a temporary measure

 

RAID6 is a good idea, not really over the top depending on how many drives you are getting. As recommended above externalizing the storage to a SAN if you could stretch to it would be a good move and make it shareable by all of the servers but it can be a little pricey in comparison.

[Ric_]

I have 2x Sun X4440 BEASTS (4x4-core CPU + 32GB RAM in each) for my hosts. They work really well and running all my 13+ VMs on one host barely breaks 15% CPU/memory usage.

 

Personally, I'd recommend you stay away from VMWare purely to keep your TCO as low as possible. Hyper-V is fine if you are comfortable clustering servers yourself and have a super tight budget. Personally, I recommend XenServer because all the basic VM goodies are in there (including XenMotion) for free.

 

You really do need a SAN though to start scaling. The S7000 series from Sun is rather good and very competitively priced.

[sidewinder]

I'll be honest, I'd never really looked at the ReadyNas before, but it does look very good indeed. Those who have one, do you run it like a SAN on its own network behind the main one, or just on the same network?

[sidewinder]

Personally, I recommend XenServer because all the basic VM goodies are in there (including XenMotion) for free.

 

That is something I need to trial tbh, I've heard good things about it

 

Oh and while this thread has been really helpful, its also given me a bit of a headache - I neglected to mention I needed to make the decision within just a few days as the finance is coming from this years budget rather than next years...

[tmcd35]

I'll be honest, I'd never really looked at the ReadyNas before, but it does look very good indeed. Those who have one, do you run it like a SAN on its own network behind the main one, or just on the same network?

 

AFAIR the ReadyNAS has iSCSI support so it can be set up as a basic SAN. I'd connect it to it's own gigabit switch seperate from your main network segragating VM data traffic from the rest of your LAN.

[dhicks]

I would like to virtualise one DC, as both of ours are out of warranty and could do with replacement. I've seen arguments for and against this, so whats the consensus? I would still keep one on a physical box.

 

We run a single live DC here, with a fail-over backup being mirrored in real time to another server, ready to take over if needed. Importantly, only one DC is running at any one time. From what I understand, this should be fine. Problems arise when you have two DCs that you take snapshots of as backups, then when you come to restore them you find the DC gets confused about the date, what workstations are in what state, etc.

 

One of the advantages of virtualisation is that it makes all hardware look the same, so you can move servers between physical machines if you want. It might be that your best strategy is to have two virtual DCs, in separate physical locations, with no snapshots taken of them - rely on Windows to synch data between the two servers. If one physical server breaks you can get new hardware without worrying about whether your DC will work on it. If one DC becomes currupted, gets a virus, etc, then you just carry on using the other DC and re-format the old DC as normal.

 

--

David Hicks

[m25man]

I'm just going to endorse what others have said here but with my own 2p thrown in,

 

It sounds like you (SIDEWINDER), are looking at Virtualisation more as a consolidation solution rather than a fully redundant clustering/failover solution.

I also like to use VM's for application isolation, we often brden physical servers with applications that are really like Oil and Water a VM can keep these troublesome mixes apart.

 

In which case you need raw horsepower to host the Guest OS's, so RAM and CPU's are key.

We use Dual Quad 3Ghz HP's but anything that supports hardware virtualisation will do! I've had 15 guests running on one of these without it breaking into a sweat.

 

As posted by others the iSCSI entry level option would be a better place to store/boot your VM's from but if you do choose to store/run them locally make sure your raid card is reasonably high spec to keep the read/write queues down.

This shouldnt be an issue with all of the Dell Raid options.

 

Also, make sure you have loads of NIC ports, the more the merrier.

Dual Quad Ports is what we use, you can't beat having a dedicated NIC for each VM if you can.

We use the onboard for Host Management and iSCSI connections and map a VM to each NIC port.

The Multiport NICs also make things like Virtual Switches easier to setup and apply.

 

If you are not yet considering clustering and failover don't put all your golden eggs in one basket!

Stick to virtualising the member servers that will not bring your site to it's knees everytime you want to tweak a setting and bring the Host down!

If you must virtualise a DC without redundancy, keep it as simple as possible so that you can V2P it easily if need be or seize roles from physical servers in an emergency.

 

Most of us can live without the AV server or the WSUS or WDS even a printserver or two can go AWOL for a while without anyone loosing any sleep but start putting DC's and Fileservers on there without proper redundancy youre heading for a whole world of hurt!

 

Once you start to look towards Virtualising DC's and other mission critical servers you will quickly realise that £20k for your first virtual server farm and SAN is more of a requirement than a request.

[sidewinder]

It sounds like you (SIDEWINDER), are looking at Virtualisation more as a consolidation solution rather than a fully redundant clustering/failover solution.

I also like to use VM's for application isolation, we often brden physical servers with applications that are really like Oil and Water a VM can keep these troublesome mixes apart.

 

Definitely, yes. Baby steps at the minute. Ideally would eventually like everything virtualised with redundancy, but our usual seemingly unlimited budget is unsurprisingly starting to be reined in, so anything major will have to be planned for a year or so in advance, if we could afford it at all.

What I'm looking at here is consolidation of some member servers, and capacity for future non critical servers.

 

As posted by others the iSCSI entry level option would be a better place to store/boot your VM's from but if you do choose to store/run them locally make sure your raid card is reasonably high spec to keep the read/write queues down.

This shouldnt be an issue with all of the Dell Raid options.

 

What does worry me slightly with the entry level SAN solutions is potential lack of bandwidth...for example the ReadyNas only has 2x1Gb ports which seems slightly limiting to me, but then again I've not had any experiance with iSCSI so perhaps that is more than enough.

Either way, for the reasons above, fibre channel or 10Gb is almost certainly out of our price range for the time being

 

Also, make sure you have loads of NIC ports, the more the merrier.

Dual Quad Ports is what we use, you can't beat having a dedicated NIC for each VM if you can.

We use the onboard for Host Management and iSCSI connections and map a VM to each NIC port.

The Multiport NICs also make things like Virtual Switches easier to setup and apply.

 

Noted, will make sure there is an extra quad port NIC or 2

 

If you are not yet considering clustering and failover don't put all your golden eggs in one basket!

Stick to virtualising the member servers that will not bring your site to it's knees everytime you want to tweak a setting and bring the Host down!

If you must virtualise a DC without redundancy, keep it as simple as possible so that you can V2P it easily if need be or seize roles from physical servers in an emergency.

 

Most of us can live without the AV server or the WSUS or WDS even a printserver or two can go AWOL for a while without anyone loosing any sleep but start putting DC's and Fileservers on there without proper redundancy youre heading for a whole world of hurt!

 

Once you start to look towards Virtualising DC's and other mission critical servers you will quickly realise that £20k for your first virtual server farm and SAN is more of a requirement than a request.

 

Definitely. From what you and others are saying, I think its probably worth keeping my DC's & fileservers physical for now, which isnt too much of a problem considering the file servers were only replaced last year anyway.

[Guest Guest]

only has 2x1Gb ports which seems slightly limiting to me

 

Its not as simple as "how much does it add up to?". The way any tcp traffic works when bonding interfaces is only 1 link can be used per host. ie if you only have 1 SAN and 1 VMserver it doesnt matter if they have 8 1gb nics, they will still only communicate at 1gb. So if you are only planning on having 2 VMservers then 2 x 1gb on your SAN is enough.

With that in mind the VMservers talk to many hosts (and indeed have many hosts on them) so 2 x 1gb or more is a must.

 

All that said, the more the better if you've got the money, as its always handy to have spare capacity for backups etc, but if you are tight on cash you can go without and upgrade next year.

 

The main thing which is likely to cause an IO bottleneck is if you skimp on HDs. The faster the better and the more the better too. Personal opinion (after using a SAN with 6 sata HDs) is 6 SAS or more is a minimum.

[sidewinder]

Anyone got any experiance of Broadberry SAN's?

They've got very good reviews in PC Pro, and the 316S is their recommended SAN,

But just wondered if anyone had used them before I contact them