10 Replies Latest reply on Aug 11, 2008 10:19 AM by endeler

    Slow disk/network performance between VMWare Clients

    endeler Novice

       

      Hi everyone

       

       

      I am struggling with my VMWares for quite a while now without having solved a general issue. I am running a VMWare Server 2 RC1 on a Dell Dimension 9200 without any RAID, 4GB of RAM. As for a host I run openSUSE 10.3 which works like a charm so far. I have different VMWare clients running on that host. When i start 2 Windows XP SP3 Clients and try to exchange large files between them the network performance dramatically slows down after a couple of seconds. Decompressing a large file on the client (800 MB) takes forever. Even copying a file from my NAS is terribly slow. There are Gigabit-switches everywhere and cat6-cables, so the wiring cannot be the problem. Copying between VMWare clients does not touch the network as I have read, so the problem must be somewhere else... but where? I appreciate every hint, cause this situation is driving me crazy Thanks in advance!

       

       

        • 1. Re: Slow disk/network performance between VMWare Clients
          Peter_vm Guru

          What do you use to monitor your host performance (CPU, Memory, Disks, Network)?

          Shouldn't you check those resources during "slow times"?

          • 2. Re: Slow disk/network performance between VMWare Clients
            endeler Novice

             

            I did not use any special monitoring tools except the monitors in the task manager. Do you propose any special tools in order to measure performance?

             

             

            • 3. Re: Slow disk/network performance between VMWare Clients
              Peter_vm Guru

              I have never seen "task manager" on SUSE, but hey, times are changing....

              "Host" in virtual terms refers to physical machine that you have your virtualization application installed on.

              Since you running Linux, you know what tools are the best, don't you?

              • 4. Re: Slow disk/network performance between VMWare Clients
                endeler Novice

                Thanks for the explanation, I obviously didn't read your post carefully enough since I know what a host is; sorry about that. I did not yet use any tools on the host machine in order to measure performance except "top" in order to see cpu consumption, which is not high at all during the copy process. The task manager on the client shows that the network performance falls from 15% to under 1% during the first minute. What do you propose me to monitor here?

                • 5. Re: Slow disk/network performance between VMWare Clients
                  Peter_vm Guru

                  Monitor your host performance (CPU, Memory, Disks, Network).

                  Check those resources utilization during "slow times".

                  • 6. Re: Slow disk/network performance between VMWare Clients
                    Paul Thomas Master

                     

                    Do you have the latest vmware tools installed on the VMs?

                     

                     

                    From your description it sounds as though you have a single disk on your host? This could cause performance issues if you are copying files between VMs.  How does a large file copy on the host performance wise, compared to a host copy.  I wonder if the network performance is low as the disk can not keep up.

                     

                     

                    • 7. Re: Slow disk/network performance between VMWare Clients
                      endeler Novice

                      Thanks for the tip. Something really seems to be odd here... that's what vmstat shows while i copy something from my vmware client to the nas:

                       

                      procs -


                      memory----


                      -swap -


                      io---- -system-- -


                      cpu----

                      r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa

                      0  8     88 154952  10120 3534116    0    0    64    52   80   47  1  3 88  8

                      3  5     88 159368  10120 3529860    0    0  1440  1070  997 2869  1  5 15 80

                      1  4     88 157628  10124 3531532    0    0   856  2282  991 2536  0  5 46 49

                      2  6     88 157876  10136 3531536    0    0     0  1910  530 1926  0  2  7 91

                      2 10     88 157876  10136 3531708    0    0   108  2636  740 1968  0  2  0 97

                      2  8     88 159416  10096 3530316    0    0  6766  1568 2719 4399  2 17  2 80

                      4  8     88 159200  10108 3530788    0    0   164  2256  572 1922  0  2  0 98

                      1  7     88 160948  10100 3528856    0    0  3076  3564 1810 3035  1 11  0 88

                      7  9     88 154328  10104 3535816    0    0  3458  1694 1623 3175  4 11 34 51

                      3  8     88 160484  10112 3529416    0    0     2  2056  534 2201  0  3  5 92

                       

                      Without copying that's what i get:

                       

                      procs -


                      memory----


                      -swap -


                      io---- -system-- -


                      cpu----

                      r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa

                      0  0     88 167400  10488 3523928    0    0    64    53   81   52  1  3 88  8

                      3  0     88 166632  10496 3523896    0    0     4    54  385 2593  0  5 90  4

                      1  0     88 165876  10504 3523956    0    0    14   186  393 2511  1  3 92  4

                      0  0     88 165596  10504 3523960    0    0     2   966  471 2277  0  3 92  4

                      1  0     88 165572  10512 3523972    0    0     4   410  415 2475  0  4 90  6

                      3  0     88 166044  10520 3523984    0    0     2    16  342 2195  0  3 95  2

                      5  0     88 165580  10528 3523980    0    0     4    82  368 2475  0  4 94  2

                      3  0     88 165584  10528 3524012    0    0     2     0  361 2506  0  2 98  0

                      3  0     88 165716  10536 3524020    0    0    54   120  354 2313  0  2 95  2

                      6  0     88 164776  10544 3524128    0    0     6    54  417 2586  3  3 90  4

                       

                      As far as I understand those values there must be a problem with the disks, right? I have the original SATAII-controller in it with 2 300gb harddisks. What can I do in order to eliminate those problems? Thanks for any tips!

                      • 8. Re: Slow disk/network performance between VMWare Clients
                        endeler Novice

                        The problem most probably has to be disk-related. What I found out so far:

                        I run 3 VMs, 1 Windows 2003 Server 64bit (Exchange) and 2 Windows XP Clients. After I have turned off Exchange Server erverything works fine and transfer rates are great. This must have something to to with Windows 2003 64bit. Does anybody have a clue? Thanks in advance!

                        • 9. Re: Slow disk/network performance between VMWare Clients
                          CLSsupport Novice

                          Tell us how many vCPUs do you have configured in your VMs and how many pCPUs do you have installed in your host ?

                           

                          You have 2 disks for 3 VMs - SATA ok - could you install a third Disk or shutdown one of the WINXPs ?

                          You wrote no RAID ? is that only a testing environment ?

                           

                          Michael

                           






                          FujSie RX300 S3 2xQC 1,6GHz 10GB LSI 6x144GB SAS 10k / WINHOST64 / VMserver20ß / WinDC32 WinTS32 WXPpro Knoppix

                          • 10. Re: Slow disk/network performance between VMWare Clients
                            endeler Novice

                            The host is an intel core duo; the guests are configured as 1 cpu machines. Never mind, I found out how to improve performance (actually to get performance at all). All I had to do was setting the disk policy to "Optimize for permormance" instead of security. Kind of strange that the security option is freezing all guests when copying stuff... but I'm glad it helped. So far I have to say that VMWare Server was so so so much more stable and better... Thanks everyone for helping me!