TM1 Forum

Hi Guys hoping I can get your thoughts on this one:

As part of a cost saving measure the business is virtulising its servers ( EDS managed) and TM1 is on the list of server to be potentially virtualised. Have any of you worked with TM1 on a virtualised server and if so can you offer any pros and cons to doing so? I am against it as it took at 8mth to get the beast + the uncertainty involved in going virtual. Would appreciate any feedback. Thought this would be the best place to post this since the majority of you guys have vast amount of experience with TM1.

Cheers
Shock

There's no blanket answer to your question - the impact has to be dealt on a case by case basis, and the only real way to determine performance etc.. is to run a TM1 pilot under the proposed vitual server insance. There's too many factors that could swing the pendulum either way here.

For what its worth, if set up correctly, TM1 running on a Virtual Server will generally behave the same as TM1 running on its own dedicated-Server. The biggest factors are generally the TM1 server memory usage & the proposed location of the sever -I'd suggest checking to see whether EDS really understand the impact this has on TM1. I've had 3rd Party IT providers propose virtualising TM1 servers without realising the TM1 model actually uses more memory than physically available on the Virtual Server.

Which virtual server tool are they looking at using?

We've been running 2 servers on a VM for 18+ months now and can't say we've had any major issues, but it does depend on your model. Ours is 32bit running on Win 2003 Server, and the model usually runs about 1.6gb in RAM during normal daily use. VMs are limited to around 3.6gb MAX on 32bit (can't find my notes but i think 64bit VMs are limited to 4GB, but that might have been 32bit software running IN a 64bit VM, can't remember) which is probably going to be the biggest question. The other is what else will be hosted as a VM on the same host as yours, something that has caught us out in the past.

Depending on the way things are setup, the host may manage its resources dynamically and divert CPU from one VM to another if its detecting a need. Our original host had about 12 other VMs, some were very hungry on CPU and network bandwidth. Originally we were fine but as these got added we noticed a distinct reduction in our performance, and once our IT guys had given me the list of VMs on our host i could see why. We had our VM moved to a "quieter" host and we got our original performance back, so that is something you'll need to keep a close eye on.

Functionality wise you'll see no difference, we're happy with it but its because our models sit well within its limits. If yours are boarderline on resources or 64bit, then you may have grounds for concern.

We have adopted a split model at my company. We use VMs to run our reporting models (very few rules) and physical servers for the rule and calculation heavy models. When we were going through our testing the main thing we discovered was that loading times for the server were significantly different, this has alot to do with your VM configuration (ie seperate SANS for the disks versus using the hard disks on your VM host). All in all we have not dissapointed by the performance on the reporting models and we plan on maintaining them in a VM.

Like an earlier post said you have to monitor it closely. IT (and I am in that category) tends to think of VMs as a great place to dump every server many times not realising the issues they are causing. TM1 is an application that took our network folks a long to time come to grips with because it is so differnt as compared to many other applications they host. the best advice is just to test it out and see if it meets your companies needs with regards to performance, much like there are no true specs to TM1, there is no good rule to virtualization of TM1.

Thanks for the reply's guys. I am now eveny more relunctant to move this across. ATM we are using close to 40gig of ram on the current 64bit installation.

Hi guys, was able to get a respone from EDS and mentioned that and asked "Will TM1 Be on a 64bit VM and Are 64bit VMs limited to 4GB??

His answer:

I believe the limit is 16GB per virtual machine but we should check during the call next week. I am setting up a call with the EDS architect and the server operational owners for Tuesday next week which you will be invited to and we can get more detail then.

So does this basically mean that our current prod instance will not work current at 20gig? I guess the only way would be to split up the cubes up and keep them on seperate virtual servers ( which aint going to happen )??

if you are using 40GB in your current 64bit server and the 64bit VM will only support up to 16GB, then its a pretty easy choice in my view. If the model can be split up, then its an option (if a hard work on your part option). If it can't be split then VM is a no go. The answer from the architect will be key...