7 Replies Latest reply on Sep 14, 2008 12:12 PM by NickViz

    recommended set up and settings for windows 2003 host, 12+ guests

    dickieblack Novice

      Hi all,

       

      I'm just getting to the point in my setting up of a virtual server that I am running out of trial-and-error guessable and googleable answers, so I thought it was time to turn to the experts.

       

      Some background: I have  a 4 socket, quad core XEON Dell PowerEdge R900, with 12gig of RAM 4 gigabit NICs and 2 73gig plus 3 146gig SAS disks. Currently it's set up with a RAID 1 array for the host OS (Windows Sever 2003 x64) and a RAID 5 for the guests (Windows XP or Server 2000/2003). RAID policy for the RAID 5 is writeback & adaptive read ahead. The page file for the host is only on the RAID 1 array. No other application or services, except SNMP, antivirus and UPS monitoring, are running on the host.  

       

      There could be up to 16 guests running at a time with 384-768meg RAM each, but most likely around 8-10. Most of those will be idle/not logged on, as the purpose of this machine is mostly to provide users with remote desktop access to expensive applications that we only have a few licenses for without setting aside physical hardware. I am not entirely sure

       

      The guests generally perform well when users RDP to them, except when they don't. Sometimes individual guests will slow to a crawl and require a reboot. Sometimes they all do and the host itself will need a reboot. Other times if I start suspending all my guests before I reboot, things return to normal. I have noticed when this happens there is a lot of physical disk access, but not much processor activity, which leads me to believe that perhaps something is not set as it should be in either the physical or virtual disk setup.

       

      What I am basically looking for (and I have looked, honest) is a set of sensible settings for the host and guests, for me to check that I have set so that I can be sure I have got the best performance out of my resources.  I have read various things about preallocating virtual hard disks (which I understand) and stopping the guests using a named file for memory, along with some other parameter settings (which I don't).

       

      I await your expert advice!

       

      Richard

        • 1. Re: recommended set up and settings for windows 2003 host, 12+ guests
          Paul Thomas Master

          Not really an answer to your question, but I'm just wondering if you would be better looking at ESXi? This is now a free download.  I would expect this to have better performance, and be preconfigured to perform.  You would need to check to see if it supports your hardware.

          • 2. Re: recommended set up and settings for windows 2003 host, 12+ guests
            dickieblack Novice

            Thanks,

             

            I have been considering that, now that it is free, but the current server is in use (yes, I know, pre-release software...) but I need to get some compatible hardware to test ESXi before I could migrate. I'm a mainly windows guy too, with very little linux experience and last time I tried ESX I had huge difficulties trying to get the server to talk to our domain for user authentication.

             

            Your reply is swaying me more towards that option, though I would still like to get some tips in mean time.

             

            Richard

            • 3. Re: recommended set up and settings for windows 2003 host, 12+ guests
              btone Hot Shot

              hi richard,

               

              if you look around in the server 2 forum you will find a lot of complaining about io performance.

              I am running beta2rc2 on linux - with 2 xp vms and 2 linux vms - and i think io perf is poor on the xp desktop.

               

              try to search around, i.e. this therad: http://communities.vmware.com/thread/146002?tstart=15

               

              it is about linux performance but some tips for vmware server tuning should work on windows as well ...

               

              regards,

               

              btone

              • 4. Re: recommended set up and settings for windows 2003 host, 12+ guests
                dickieblack Novice

                Thanks btone,

                 

                I'd already seen that thread, but couldn't find anything useful from it - because it's all linux related, it didn't sound like the same settings would affect/could be adjusted in windows. If this is not correct, I will try changing them, if someone can point me to the equivalent config file etc that would be very useful.

                 

                Richard

                • 5. Re: recommended set up and settings for windows 2003 host, 12+ guests
                  Expert
                  dickieblack wrote:

                  Thanks btone,

                   

                  I'd already seen that thread, but couldn't find anything useful from it - because it's all linux related, it didn't sound like the same settings would affect/could be adjusted in windows. If this is not correct, I will try changing them, if someone can point me to the equivalent config file etc that would be very useful.

                   

                  Yeah, the .vmem file dirtying/tmpfs workaround stuff is all mainly for Linux, you shouldn't need to worry about this on Windows.

                  • 6. Re: recommended set up and settings for windows 2003 host, 12+ guests
                    Expert
                    rrdharan wrote:
                    dickieblack wrote:

                    Thanks btone,

                     

                    I'd already seen that thread, but couldn't find anything useful from it - because it's all linux related, it didn't sound like the same settings would affect/could be adjusted in windows. If this is not correct, I will try changing them, if someone can point me to the equivalent config file etc that would be very useful.

                     

                    Yeah, the .vmem file dirtying/tmpfs workaround stuff is all mainly for Linux, you shouldn't need to worry about this on Windows.

                     

                    Couple of other things to keep in mind: running antivirus software on the host will incur a significant performance hit, as will RAID-1 on the host. Both of these significantly impact the write path. I realize that you may require both of them, I'm just pointing it out ;-(.

                     

                    Also, are you running UP (single CPU) or SMP (multiple CPU) guests? I would highly recommend against running any multi-CPU guests for your setup, it will dramatically reduce performance/throughput/responsiveness since you've overcommitted the host CPU resources, which is an extremely difficult scenario for our hosted (Server/Workstation) products to deal with since they don't control the scheduler of the host OS.

                     

                    Finally, as the other poster noted, it definitely sounds like you should really be running ESXi for your workload. Usability should have improved significantly since you last looked into it, and (I would hope that) you could get it up and running without needing to know anything about Linux or shell commands).

                    • 7. Re: recommended set up and settings for windows 2003 host, 12+ guests
                      NickViz Novice

                       

                      Well, if you already found and tried common tips (like using SCSI VM disks, preallocating, tuning .vmx file), you can try the following:

                       

                       

                      if you don't need redundancy (well, with daily images backup you might not need is so much), break the RAID5 array onto 3 separate disks and allocate your VM evenly. You will get 3-4 VMs per SCSI disk and I guess it delivers enough hdd power. Also one consuming machine can't affect all the rest (only 2-3 neighbours).