[sims] Sticking with physical Sims setup or move to Virtual?

[maxrebo]

Our Sims server is due a upgrade this summer from Windows 2k8r2 to 2012r2, i was going to get our LA to do a clean instLl on the current physical box im thinking more and more about virtualising it

Can anyone suggest any reason why its a bad idea the VM this?

Ive read on here that lots of people have done it and had no problems

[bobsmith]

Nope, no reason that a sufficiently well spec'd VM would be a bad idea.

 

The benefits of a VM have got to outweigh any costs. Plus with SIMS 8 due for secondaries in the next 12 months (or so) I wouldn't be chucking money at a physical server which you may be doing away with.

[mrwoberts]

Max,

I've done this recently and it was easier than I was expecting.

The host is relatively beefy, but each VM (1 for DC, DHCP, DNS; 1 for SIMS DB)

In fact, the VM didn't need that many resources because I was using SQL 2014 Express (we're a Primary school).

Runs smoothly.

[vikpaw]

Defo go VM, no massive reason not to. Especially if you're going for a clean install anyway.

I did a P2V conversion when we first went virtual, then later did a clean install.

In the old days Capita used to complain if there was an issue with performance, but lately, it's well supported, so long as any issues are intrinsic to SIMS.

The bonus of snapshots and being able to rollback from a failed update is priceless.

[ITGURU]

I'll always be Physical server for SIMS for me - Dedicated sever with dedicated disks gives the best performance than a VM with a VHD as it's heavily used.

[TwistedHelixis]

All my primary schools have sims on hyper-v. Much better for lots of reasons.

[TwistedHelixis]

The bonus of snapshots and being able to rollback from a failed update is priceless

Was under the impression you should only do that with Server 2016 as the other previous versions can (apparently) cause an issue with sql databases.

[3s-gtech]

My SIMS server is virtualised, but when I transferred the VM to its current host on ESXi I stuck some SSDs into the host as a separate array - this is where the VM lives. It's quick as a result.

[mrwoberts]

Was under the impression you should only do that with Server 2016 as the other previous versions can (apparently) cause an issue with sql databases.

I read something similar. 2016 Hyper-V has variants [of checkpoints] I believe (Production and Standard). Production provides a flawless reversion, according to this Veeam article...

 

https://hyperv.veeam.com/blog/what-are-hyper-v-snapshots-12-things-to-know/

 

I suppose that's another good thing about going Hyper! Upgrading your Host 2012-2016 seems to be relatively straightforward.

Edited May 20, 2017 by mrwoberts

[maxrebo]

If im honest, i dont actually get snapshots, i know what they are but when are you supposed to use them?

I have a veeam setup so if a VM went corrupt i would just restore from previous night

 

Anyone care to explain how to use them in my setup?

[mrwoberts]

If im honest, i dont actually get snapshots, i know what they are but when are you supposed to use them?

 

Snapshots are definitely not to be used as an alternative to backups, but they are excellent for those what-if, point in time 'snapshots'. Whereby, for example, you were ready to install a bunch of selected updates on your server, but heard rumours that one of them may cause a BSOD. Well, you'd first take a snapshot of the VM, install the updates, run through a bunch of stability tests and if all seems well you simply merge/remove the snapshot. However, if it did cause a BSOD on your VM, you'd simply rollback the snapshot, which is fairly instant. Achieving the same thing with Veeam would take much longer. Does that help?

[dapaulio]

+1 on Mrwoberts comment.

Just remember to remove the snapshots once you dont need them as they don't half eat away at your storage. Not so bad if you have a San with tonnes of storage but like some of the primaries we look after have a single HV with maybe 2 tb volume for vhd. It soon consumes it if you don't managed your snapshot well.

[maxrebo]

Yes dont i know it, we had our veeam backups replicating after nightly backup and for some reason it wasnt removing the snapshots, kept building up and then corrupting the VM.

[maxrebo]

Yes that makes alot of sense

[TwistedHelixis]

Always a but - Sometimes the snapshot can fail to merge and corrupt the vm. I prefer the longer restore from backup method, its not like the old days of having to restore a physical server anyway.

[maxrebo]

Yeah thats the part that worries me with having it as a VM.

I would first like to understand with these snapshots fail to merge.

[TwistedHelixis]

Even with snapshots not in the equation its still a lot better to have everything virtualized. Restoring a VM is so easy then I quite often do it just to test something, I restored two last week which you would not be able to do on flat hardware.

[TwistedHelixis]

So for example, if I need to migrate Sims to a new SQL version, I can restore my sims server to a test host, see if it all works OK and make any notes before doing it for real. Edited May 20, 2017 by TwistedHelixis

[vikpaw]

Never had a problem reverting to snapshots. I used, VMWare though, not sure if the issues mentioned are Hyper-V related.

 

A snapshot is like a diff file, it's compared to a previous known state. You could think of it like a system restore point. The difference is, a snapshot can be taken at any stage, potentially mid way though an installation of software, a bunch of files being transferred etc. In practise it will freeze the machine.

 

Everything in a VM, RAM, "disk" space, peripherals are just fake entities for the most part, saved to a disk array somewhere. All a snapshot does is backup it all up and then starts recording any future changes made to the disk. When you revert to a snapshot, you ignore all those diffs/changes.

 

When you delete a snapshot you are accepting all the changes up to the next snapshot, so it will update the diffs forward in time to the next snapshot. This is where it can take time and potentially cause corruption.

 

I used to keep loads of them and only merge/delete over the summer. Now I'd recommend only keeping one for a testing scenario so you can quickly "undo".

 

Backups, though slower are a more reliable means of system restore.

[dapaulio]

Always a but - Sometimes the snapshot can fail to merge and corrupt the vm. I prefer the longer restore from backup method, its not like the old days of having to restore a physical server anyway.

Best practice for snapshots is to take one whilst the vm is in off state. Not saying it wont ever happen but i never personally had a problem merging and taking snapshots myself and I have taken snaps whilst in an on state.

[Banjo]

We use ESXi and it works fine. We don't stack more than 1 OS on the physical box, but the advantage comes as the VM makes the management of the servers easier if anything goes wrong.

[PotNoodleTech]

Virtualised the SIMS server years ago. There's absolutely no reason why any server you set up should be physical in my humble opinion. Only physical server I've got is a DC as back in the old days it was frowned upon to virtualise DCs, but gonna virtualise that too in the summer hols.

[vizubeat]

We don't stack more than 1 OS on the physical box

Are you saying you only run one VM per physical box, or won't run a Linux VM alongside a Windows VM homed on the same physical host?

 

In either case, why?

 

P2V'd our 2008 SIMS server a couple of years ago, no problems. Snapshots are so useful, will definitely be used when it comes to upgrading. We have even used them for SIMS upgrades - I know a backup is taken anyway but...belt and braces. It takes no time so it just becomes a natural step.

[TwistedHelixis]

Must say, I would love to see how many people do or don't snapshot SQL / Sims, and DC's for OS 2012r2 and below.

[Banjo]

Are you saying you only run one VM per physical box, or won't run a Linux VM alongside a Windows VM homed on the same physical host?

 

In either case, why?

 

P2V'd our 2008 SIMS server a couple of years ago, no problems. Snapshots are so useful, will definitely be used when it comes to upgrading. We have even used them for SIMS upgrades - I know a backup is taken anyway but...belt and braces. It takes no time so it just becomes a natural step.

 

We only install one VM per box. The servers that the VM and SIMS sits upon meets the specs for SIMS with headroom. When you start adding other VM's then you have to go back and look at hardware side again, which pushes costs up. We have an image with SIMS installed and ready to go (just missing the DB & Docs). If a server goes bang or gets stolen we can drop this image on a new box and download the SIMS backups and have it in place on site in 1/2 a day.