2 Replies Latest reply on Apr 10, 2008 5:14 PM by twwlogin

    RHEL 5 performance abysmal

    twwlogin Novice

       

      We have a RHEL 5.1 host (2.6.18-53.1.14.el5 kernel) with (2) dual-core AMD 2.8Ghz CPUs, 32G RAM. This host has 8 guest VMs, 6 of which are various versions of Redhat, and two of which are Solaris 10/64-bit. The versions of Redhat are Redhat 7.1, 9, Enterprise 2.1/x86, (2) 3/x86_64, 4/x86, 5.1/x86. Performance on all except the 5.1/x86 guest are acceptable. The 5.1/x86 performance is abysmal. All guests are configured without runtime information and without logging enabled. The 5.1/x86 guest is configured with 1 CPU, 2GB RAM. The virtual machine version is 6. I created a new 5.1/x86 guest with 2 CPUs, 4GB RAM, virtual machine 6, runtime information disabled, logging disabled and encountered the same abysmal performance. The 5.1/x86 guests are runnint the latest RHEL 5 release with up-to-date patches. The standard kernel is running in the guest VM.

       

       

      Anyone with an idea why the 5.1/x86 guest performance is so terrible? I'm currently installing a 5.1/x86 guest on Server 1.0.x and performance, during the install, is very good.

       

       

        • 1. Re: RHEL 5 performance abysmal
          Expert

           

          twwlogin,

           

           

           

           

           

          Can you quantify the performance degradation that you are seeing (i.e. it ran at X speed on Server 1.0x but now running at X+1 on Server 2.0 Beta 2)

           

           

          • 2. Re: RHEL 5 performance abysmal
            twwlogin Novice

             

            I shut down all other guests on the beta2 server except for the RHEL

            5.1 host. On the 1.0.3 host, I installed RHEL 5.1 with latest patches.

            The 1.0.3 host also has 4 VMs running (Solaris 10/x86-64, RHEL 7.1,

            RHEL 3/x86, Windows XP). Only the RHEL 5.1 guest on the 1.0.3 host was

            doing anything though. The rest were idle. Compiling zlib-1.2.3 on

            beta2/1.0.3 took approximately the same time, ~0.90s. With 5 VMs active, but quiet, on the 1.0.3 host, including the RHEL 5.1 guest, performing the zlib build takes ~1.20s. With 8 VMs active, but quiet, on the beta2 host, including the RHEL 5.1 guest, performing the zlib build takes ~2.00s. On the beta2 host, if I run ./configure on GNOME Evolution on 3 of the VMs, and build zlib on the RHEL 5.1 guest, the zlib build takes ~1.30s. On the 1.0.3 host, if I run ./configure on GNOME Evolution on 3 of the VMs, and build zlib on the RHEL 5.1 guest, the zlib build takes ~2.20s.

             

             

            Maybe I've over-subscribed the CPUs on the beta2 host?