Running LCS 2005 in a Virtual machine

Lena sent me a mail the other day about Virtualisation.

Hello Eileen,

I ran into a series of notes between you and several others about running SMS2003 on VMs.  Have you had any experience with running LCS 2005 on VMWare?  I would imagine that performance would be impacted for a VM hosting over 3,000 LCS clients……..thoughts?

Thanks.

She was also concerned about placing inappropriate applications on VMs.  She thought that VMs are great for test/dev and demos, but to run production LCS Enterprise hosting 5,000 active users on shared hardware that barely meet the minimum requirements of LCS itself would be a little concerning.

Well, my first thought was yikes! For a start, John is our Virtual guru (What I mean by that is he actually exists in the real world and he’s our expert on Virtualisation) so I wanted to just forward him the mail, but  we do actually run LCS 2005 in our test and demo environments in VM’s, and  we also run scalability tests within VM’s.  Outside of the normal performance hits that exist with running anything in a VM, I haven’t found any discernable additional hit with LCS .  Presence information about the user is stored in MSDE or SQL server so you should take care should be taken where you locate of these databases.
Active users in sessions aren’t a significant impact to the guest OS, so shouldn’t  really impact performance. The only issue to be aware of is when you use archiving and logging. As this uses SQL server, then the database should be placed to take account of the high I/O.  I’d put this on the host machine
LCS standard edition uses about 1.6kb per day for each active user and can host up to 12,000 active users (that is users actually in session).  You can have a look at the scalability documentation to give you a better guide to the sort of hardware to use for this size deployment
Have a look at the documents I mentioned in my blog entry  from the other week.  We use Virtual Server and Virtual PC – so the performance overhead may differ from VMWare…