12 Replies Latest reply on Oct 1, 2008 1:44 AM by mctz

    Poor win2003 guest performance on linux host vs win2003  host

    mctz Novice

       

      Have just updated to VMWare Server 2.00 GA from rc2 and for the first time have compared guest performance using two different host O/S on the same hardware.

       

       

      The box has a quad core X5355 cpu @ 2.66GHz with 16GB RAM.

       

       

      The guest config is Win2003 x86 (single cpu).  The two host configs are Win2003 32bit and OpenSuse Linux 11.0 64bit with latest patches etc. Memory trimming switched off.

       

       

      We used a benchmark tool in the guest called  Sandra Lite2009.

       

       

      Disk performance was comparable. (The virtual disks were kept on an NTFS partition used by both host O/S).

       

       

      Memory-intensive performance was poor with the Linux host...most of benchmarks put it at about half the performance of the Windows host benchmarks.

       

       

      The difficulty at this point is determining whether VMWare is to blame or if it's something that is not optimal in the Linux host config itself.

       

       

      I'd like to be able to somehow compare performance of the two hosts, but across different O/S I'm not sure how you would do this.

       

       

      Also I do remember seeing a thread in the Beta forum (which I can't find now) that criticised the VMWare behavior on Linux compared to Wiindows in respect of memory management...something to do with the disk-backed nature of the guest's memory footprint?

       

       

      Appreciate any advice...this seems like too bigger performance penalty for taking the jump to 64 bit land. (I was more attracted to migrating onto a lean 64bit Linux kernel than going to Windows 2003 64bit.)

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

       

        • 1. Re: Poor win2003 guest performance on linux host vs win2003  host
          pasikarkkainen Enthusiast

           

          How about trying 32bit linux host OS aswell?

           

           

           

           

           

          • 2. Re: Poor win2003 guest performance on linux host vs win2003  host
            mctz Novice

            Because I don't have any spare partition space to put a third O/S! But I agree it would be interesting to see how this compares too.

            • 3. Re: Poor win2003 guest performance on linux host vs win2003  host
              andreas.eckstein Novice

              ... deleted ...

               

               

              (Just noticed I was answering to the wrong topic alltogether. Sorry 'bout that.)

              • 4. Re: Poor win2003 guest performance on linux host vs win2003  host
                dlegg Novice

                 

                Don't know, and it could be anything before you blame memory performance in the Linux host. I have SQL Server running on a Windows 2003 guest running on a CentOS 5.2 host and I haven't noticed anything untoward. To be honest, my impression of performance within guests running on a Windows host has not been favourable.

                 

                 

                Could you try and narrow this further as a Linux problem by using another host OS, possibly Red Hat or CentOS?

                 

                 

                 

                 

                 

                David

                 

                 

                • 5. Re: Poor win2003 guest performance on linux host vs win2003  host
                  Scissor Virtuoso
                  mctz wrote:

                   

                  ...We used a benchmark tool in the guest called Sandra Lite2009...

                  According to the "Performance Best Practices and Benchmarking Guidelines" at ( http://www.vmware.com/support/pubs/ws_pubs.html ):

                   

                  -


                  Discouraged Benchmarks
                  We don’t recommend use of the following benchmarks, as our experience has shown that they can produce
                  inconsistent results in virtual machines:

                  • Sisoft Sandra

                  • LMbench

                  • Unixbench

                  -


                   

                  Granted the guide was written for VMware Workstation 6.5, but I'm sure it also applies to VMware Server.

                  • 6. Re: Poor win2003 guest performance on linux host vs win2003  host
                    mctz Novice

                     

                    Thanks for that link Scissor. Even though Sandra might product inconsistent performance running in a guest, we were doing a comparison of the same guest running in different hosts so I would have thought there would have still been some relativity about the results, but we'll take the advice and try one of the recommended ones.

                     

                     

                    Will post back results ...

                     

                     

                    • 7. Re: Poor win2003 guest performance on linux host vs win2003  host
                      mctz Novice

                       

                      Very interesting...

                       

                       

                      Using the lite (free) version of PassMark's PerformanceTest  (one of the packages recommended in the document), gave much more consistent results. Clearly the timing measurements in Sandra must be screwy when used in a guest VM.

                       

                       

                      This was only a real quick and dirty comparison, but:

                       

                      • For the memory speed tests, we found the Windows guest running under Suse 11 (64bit) was about 5 to 10% down compared with Win2003 (32bit) as the server.

                      • CPU performance was pretty much line ball between the two.

                      • Disk performance ...ntfs performance (for the vdisk) under linux was down about 20 to 25% on windows host. But using ext3 - as you would do - puts the two contenders on a par, but results are quite dependent on the block size used in the tests.(The bigger the block size in a sequential write tes, the better ext3 compared to ntfs). Somewhat surprisingly to me, these tests became progressively cpu bound with larger block sizes.

                       

                       

                      Also compared these results with the same tool running in the (Windows) host itself, and the guest performance overall was only degraded by a small and acceptable margin compared to the host.

                       

                      So all in all I'm not unhappy with these results, although somewhat puzzled why host=linux-64 is still slightly lagging performance of host=windows-32, when I had expected it to be the other way around based on what others have said.

                       

                      I would be very interested in these sort of comparisons from anyone else...just to see if these results are typical.

                       

                       

                      Thanks,

                       

                       

                      MT

                       

                       

                      • 8. Re: Poor win2003 guest performance on linux host vs win2003  host
                        btone Hot Shot

                         

                        I guess you mean this thread!

                         

                         

                        "The big-picture answer is that the Linux virtual memory subsystem is simply not tuned for running VMs. No OS can be the best at everything. If you really want to be at the higher ends of transfer rates for your storage devices, ESX is a much better option - ..."

                         

                         

                         

                         

                         

                        After this I was thinking to test virtual box on my ubuntu host - but I really like vmware server and with only a few vms the performance is ok for me though the windows vms are quite slow....

                         

                         

                        • 9. Re: Poor win2003 guest performance on linux host vs win2003  host
                          mctz Novice

                           

                          Ah, yes, that is the one.

                           

                           

                          I haven't tried this out with a whole lot of Windows VM's, but at the moment the two host O/S choices seem to offer close enough performance that I will be happy to run with Linux. I will also probably use a number of Linux guests for things that currently are Windows, simply to make it leaner and meaner, also to take advantage of paravirtualisation if I can.

                           

                           

                           

                           

                           

                          • 10. Re: Poor win2003 guest performance on linux host vs win2003  host
                            btone Hot Shot

                            hi mctz,

                             

                            I am running one ubuntu 8.04.1 jeos  guest with para virt support. it performs really great... and I just love debian based distris and with 5 years support its my choice for linux guests....

                             

                            regards,

                             

                            btone

                            • 11. Re: Poor win2003 guest performance on linux host vs win2003  host
                              mctz Novice

                              I'm interested to hear you say that...I have actually built a guest VM with JeOS when 8.04 was first released, and I really like that idea.

                               

                              Do you have any sort of comparison of performance for something 'real worldish' such as a J2EE server, or just Tomcat/Servlets/JSP/Java between JeOs and Windows on the same host?

                               

                               

                               

                              I started out looking at using Ubuntu for host, but ended up going down the SuSe road for a couple of reasons. But Suse don't seem to have an equivalent skinny build of the O/S to match what JeOS aims to do. I'm assuming it shouldn't matter that I might use JeOs as a guest on a SuSe host? Also, why is there no 64bit JeOS build?

                              • 12. Re: Poor win2003 guest performance on linux host vs win2003  host
                                btone Hot Shot

                                Sorry, cant offer any real world performance comparison - its running an ssl gateway - java based. Compared to the windows guest it really "feels" better - just like a physical machine....

                                 

                                My host is running ubuntu 64bit - but I think you are right - it doesn't matter what linux distri you are using on your host.

                                 

                                And I have no clue why there is no 64 bit version of jeos...