SAS on Virtual Machines

[RupaJ]

Hello,

I have a generic question. What are the performance impacts of running SAS on VMs? More specifically can we choose a VM for metadata server, since all the processing happens on the compute anyways. For a smaller size SAS system (8 core compute and 4 core meta), we are thinking of having a VM for meta server to cut costs. I was wondering what would be the performance impact if any. 

I also reached out to SAS and they did provide me the best practice document on this. However I would like to hear more thoughts on this. Appreciate your time and response!

Here is what SAS provided - paper SAS Technical Support provided

Thanks!

[kjohnsonm]

I cannot help you on the "can we choose a VM for metadata server", I am sorry, but I have found that VMs work very nicely on all uses of SAS windows desktop work other than Sankey diagrams they seem to be a bit slower being graphical in nature.  In fact my local office does not have that great of network wiring and the VM server and the SQL DBs I typically connect to are in the same server room my performance seems to be much faster for general selects and computation.  I hope this helps -KJ

[MargaretC]

What do you mean by Virtual Machines?  Do you mean a machine with VMware running on it, but the cores and memory are dedicated to just the application (i.e. thickly provisioned), or do you mean a virtualized infrastructure where memory and cores can be “stolen” at a moments notice if another virtual machine in the infrastructure needs them (i.e. thinly provisioned)? 

SAS runs in both, but prefers to be on a thickly provisioned infrastructure. 

Also, depending on the network activity between the various SAS components, your SAS Metadata server may need to have a 10Gigabit dedicated network card (NIC) in order for SAS to perform optimally. 

So, what is Margaret trying to say?  You can use a virtualization tool to take an 8 core system and turn it into a 4 cores system for SAS Metadata and it will function.  Will it function without issues and perform well, that will depend on what the others 4 cores will be used for.

Margaret

[SASKiwi]

We run most of our SAS servers on VMware and get entirely acceptable performance. In our experience a well-designed and maintained VM infrastructure can outperform hardware-based versions over time as hardware tends not to be upgraded. 

[Kurt_Bremser]

We have a single-tier server setup, and run it on a AIX LPAR, and are very happy with it. The physical server underneath the VM(s) needs to be able to satisfy the computing requirements of your SAS setup, and the VM(s) need to be defined accordingly. That's all.

Having a VM enables us to have a very simple failover strategy: if the main datacenter suffers a mishap, we just have to boot the image backup of the root volume group in the secondary DC, and are up and running with the previous day's system state (since all the data outside the root VG is mirrored synchronously, we would only "lose" the results of tasks running at the moment of failure).