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Justin

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VM Hardware Recommendations

Hi experts,

I'm looking for guidance on my first VM host. Currently have 1 physical server running many roles on server 2K8R2. Was hoping I could run 3 VM guests comfortably dependant on cost.
VM guest 1: P2V of server 2K8R2, running a Point Of Sale SQL database with 6 connections.
VM guest 2: file server, WSUS, print server, etc.
VM guest 3: future expansion (AD)

I need a rack mount server from an Australian retailer. Currently browsing the 1RU Dell offerings. Host OS will most likely be hyper-v. It's for a not for profit community organisation, so cost is a a big factor.

What kind of hardware specs should I be aiming for, and why?

Thanks!
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Lee W, MVP
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You need fast disk and RAM.  CPU is not so important.

I would suggest reading my article on Virtual or Physical, which includes some guidance and links to guidance on configuration.
https://www.experts-exchange.com/articles/27799/Virtual-or-Physical.html
First, such an acquisition is capital and it should have a 3 year amortization, so don't scrimp on cash in order to regret it later.

You want 24 GB memory per server or more so 96 GB of total memory (maybe even 128 GB of available memory space).

You would have to size the disk but LOTS of terabytes of disk space (done in a Raid 10 array setup). There is never any letup in disk space requirements so scope out the room and controller to begin with.

Then a good fast CPU.
I disagree with some of John's assertions.  24 GB per server is overkill.  The database server could use it... MAYBE.  It depends on the number of transactions it will need and the frequency with which you need to access data.  The file server can likely get by on 2-4 GB.  The DC definitely won't need more than 4 GB and 2 should be fine.  Most DCs, when using Dynamic memory use LESS than 2GB.

When I say CPU is not important, you don't 16 cores or something silly like that.  Aside from licensing considerations in the future, the most important thing is GHz.  8 cores total should be more than acceptable.  Keep in mind that you WON'T want to assign more than 2 cores to any server to begin with.  (Read my article above - it explains why with reference to a third article on the subject).  Go with the fastest GHz you can afford.

Disk *IS* very important - You'll be running 4 systems off a single set of spindles based on your stated goal - that's a LOT of disk activity - you NEED fast disk that can handle that.  If disk performance becomes an issue, you can setup dedicated spindle sets and assign them one to a VM - but you may need external storage OR extra drive bays to do so.

I'll add the server you purchase should SUPPORT more than 32 GB of RAM, but to open, you can probably do just fine with ALL systems running off 32 GB.
I'll add the server you purchase should SUPPORT more than 32 GB of RAM  Yes, I agree. I was just using 24 GB to get to a total. You say more that 32 GB total and I was saying allow for 96 Gb total (no need to fill it the first day).

The most common mistake I see in here is too little disk with no ability to expand easily and limited memory per VM. It is easier (and long term cost efficient) to plan big to allow for later.

This is a business approach, not necessarily a technical approach.
Also have a read of this EE Article, and you'll start to get an idea of what to include in your purchase

https://www.experts-exchange.com/articles/13256/Some-Hyper-V-Hardware-and-Software-Best-Practices.html

look at the Dell R630s
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Hector2016

Regarding the Disk storage, it is better for you to use RAID5 for file storage, that will let you use the physical disks more efficiently than with RAID1 or RAID10.  
For example: If your physical server has 8 SAS disk bays, and you purchase 8 disks of 1TB each, then if you use RAID5 you will have 7TB of storage ready to use, but if you use RAID1 then you will be seeing 4TB only. SSD disks are faster, but they are expensive.

RAM is more important than CPU most of the time.
RAID5 is no longer recommended as suitable for an enterprise computing environment!

RAID6 is, because it can support 2 disk failures.
The author of the question is on a low budget organization, they are not forced to use Enterprise Computing Environment standards. With RAID5 they will be able to recover from a single disk failure without hassle, and that's pretty enough for small organizations all over the world. Using RAID6 the storage capacity will be lower, meaning they will need to buy bigger (and more expensive) disks to use the same amount of TBs.
Haven' tested RAID 6 but RAID 5 takes a potentially serious hit on writes.  RAID 10 or SSD drives is the what should be done.  RAID 10 in the server is still FAR cheaper than buying 3 servers!
I don't even use RAID5 for my home stuff.

Up to the Author of the Question, what he wants to use and gamble with! If he is also putting all his eggs in one basket, he also want to reduce the risk of failure!

Storage is cheap as chips.
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Philip Elder
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Hi experts,

Thanks for all your comments. The articles and information posted are great as a guide for best practise in virtualisation, thanks!

I have been been shopping online and making some theoretical builds, and it seems that virtualisation (if done right) is expensive.

So, the server currently has:
  • POS database is MS Dynamics RMS SO. It has a minimum of 4 users, average 6, max 10. (4 registers, and the remainder are back end users).
  • File server users has around 8 or 10, with their user files hosted on the server (desktop, documents, ect). The bulk of the storage is on a NAS, connected via iSCSI, since the server maxed it's storage out (Server only has 2 x 500gb SATA drives in RAID 1 with a super entry level hardware RAID controller)
  • There is a split MS Access database with the backend on the server - 3 users.
  • WSUS serving 23 PC's.

I should mention that all this and some other bits and bobs were running on an i3-2120 with 4gb of RAM. I had to upgrade the RAM, as WSUS was maxing it out when I was trying to look at the console.

So, its seems that going for a dual socket server is cheaper for me (to reach the 8 core target recommended):

  • 2 x Xeon E5-2603 v3 (6 core, no turbo or HT)
  • 2 x 16gb 2400MT/s dual rank x8 data width
  • SAS RAID controller with 1gb NV cache capable of RAID 6
  • 4 x 1.2tb 10k SAS 12Gbps HDD's

Website price is about AU$7400.

I feel like I'm on the right track - maybe a bit overboard for what I'm running, but following best practise, right?
That is pretty reasonable overall. Make sure you can add RAM if need be (may not be a need).

Make sure you can add a couple of disk drives if need be.

Otherwise decent and yes on the right track
Sometimes you can have unfortunate problems where in order to make sure you have the ability to expand, you NEED to overcommit to start.  For example, the Dual socket system may be required to get more than 32 GB of RAM.  You could probably get away with a 6 core, or even a 4 core with HT.  But you'd want to be careful... and prepared to add another CPU to an empty socket (and doing that can be tricky sometimes - which can make it better to just get it all at once.

The access database doesn't matter - none of the processing for that happens on the server - unless you convert the backend to SQL (which I would likely recommend for reliability purposes).
8 cores are required for what exactly?

We build standalone and clustered Hyper-V and Scale-Out File Server cluster environments for on-premises and cloud services.

The server hardware I outlined would be more than enough to run a less than 25 user shop with a fairly demanding SQL setup. BTDT
Can anyone point out why a R630 would be so much better than a R620 which you can get new for almost $800 less?
Newer tech means better efficiency. More CPU/Watt.
For their requirements more CPU isn't going to make much difference, the disk I/O and quantity of RAM are what'll make the difference. Consider RAM speed for example, all very useful if you're doing maths (or running STREAM benchmark) but minimal difference if you're running commercial applications (or running SPECint benchmark). Good reason to use just one CPU though.
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ASKER

Thanks again for your responses experts. Best feedback I've received on experts exchange to date.

As for the 8 cores idea - I was just going off Lees comments that 2 cores would be plenty, but no more than 2 cores per entity (2 for host, and 2 per guest = 8 cores). The E3-1270v5 only has 4 cores. So do I only need 1 core per entity? Normally I would have said the more the better (for everything), but the article seems to indicate the opposite.

As for what model to go for on the Dell website, well the options are endless. I played around with a heap of options, but its gets a bit out of control If i were to list them all here. I looked closely at both the R630 and the R330.

Andrews article said GHz over cores. Lee said get the highest GHz I can afford. Philip has suggested a high GHz processor. So, from a cost perspective, the R330's options seems to beat the R630's on GHz (even though I can get more cores on the R630).

My interpretation of Lee's article would be that 32gb of RAM would suffice (8gb per entity). I would have thought 64gb was overkill (I don't plan on too much future expansion for the lifetime of this hardware - I have already allowed for 1 spare guest).

Not sure if the budget will stretch to the suggested 8 HDD setup. Do I need 8 disks to run my intended setup, or would I get acceptable performance with 4? (I'm guessing not).
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We would go with the maximum number of disks at the smallest size to meet the needs for the next three to five years of solution life.

GHz is king in our experience. There are not too many situations where more cores (vCPUs) makes a difference to the guest and its performance.

Disk I/O tends to be the biggest limitation thus the recommendation.
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Thanks experts, lots of great information. I feel much more confident in purchasing a server that will suit my needs!