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Can't fully utilize CPU

Discussion in 'Proxmox VE 1.x: Installation and configuration' started by ymmot04, May 26, 2011.

  1. ymmot04

    ymmot04 Member

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    I have a 48 core Dell Poweredge R815 (4 chips x 12 cores) and I can't seem to use more than 33% of the CPU with a single VM. I've got a Windows Server 2008 KVM installed and I've been playing with the CPU/core settings and for some reason it seem like each Core I add utilizes 1 physical core. The problem with this is Proxmox has a max of 16 and this server has 48 meaning my VM can only utilize 33% of the CPU. When I run the VM at 100% CPU the node is only running 33%.

    Is this a limitation of the software or is something not working right? I was under the impression no matter how many virtual CPUs/Cores you assign the VM it should be able to use 100% of the physical CPU available.

    I am using the most recent version of Proxmox.

    Has anyone else had this issue?
     
  2. dietmar

    dietmar Proxmox Staff Member
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    That is the maximum cores, which is multiplied by the number of sockets you assign!

    So you can simply assign 4 socket each using 12 cores (= 48 threads)
     
  3. tom

    tom Proxmox Staff Member
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    does it work if you enter the values (4 sockets, 12 cores) in the VMID.conf file? (see /etc/qemu-server).

    and also post the output of 'pveversion -v'
     
  4. ymmot04

    ymmot04 Member

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    It does not work if I put those values in the configuration file. I tried with 4 sockets, 12 cores, and also 4 sockets, 5 cores. I get this error in the log.

    "VM 101 start failed: command '/usr/bin/kvm -monitor unix:/var/run/qemu-server/101.mon,server,nowait -vnc unix:/var/run/qemu-server/101.vnc,password -pidfile /var/run/qemu-server/101.pid -daemonize -usbdevice tablet -name Server2008 -smp sockets=4,cores=5 -nodefaults -boot menu=on -vga cirrus -tdf -localtime -rtc-td-hack -k en-us -drive file=/var/lib/vz/images/101/vm-101-disk-1.raw,if=ide,index=0,cache=none,boot=on -drive file=/var/lib/vz/template/iso/server2008.iso,if=ide,index=2,media=cdrom -m 64000 -netdev type=tap,id=vlan0d0,ifname=tap101i0d0,script=/var/lib/qemu-server/bridge-vlan -device rtl8139,mac=2A:56:D4:36:39:B2,netdev=vlan0d0 -id 101 -cpuunits 1000' failed with exit code 1"

    If I reduce it back to 4 sockets, 4 cores it starts fine.

    'pveversion -v' returns:

    "pve-manager: 1.8-15 (pve-manager/1.8/5754)
    running kernel: 2.6.32-4-pve
    proxmox-ve-2.6.32: 1.8-32
    pve-kernel-2.6.32-4-pve: 2.6.32-32
    qemu-server: 1.1-30
    pve-firmware: 1.0-11
    libpve-storage-perl: 1.0-16
    vncterm: 0.9-2
    vzctl: 3.0.24-1pve4
    vzdump: 1.2-11
    vzprocps: 2.0.11-1dso2
    vzquota: 3.0.11-1
    pve-qemu-kvm: 0.14.0-2
    ksm-control-daemon: 1.0-5"
     
  5. ymmot04

    ymmot04 Member

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    This is a fresh install that I am testing on BTW. I also tried updating everything:

    "pve-manager: 1.8-17 (pve-manager/1.8/5948)
    running kernel: 2.6.32-4-pve
    proxmox-ve-2.6.32: 1.8-33
    pve-kernel-2.6.32-4-pve: 2.6.32-33
    qemu-server: 1.1-30
    pve-firmware: 1.0-11
    libpve-storage-perl: 1.0-17
    vncterm: 0.9-2
    vzctl: 3.0.26-1pve4
    vzdump: 1.2-12
    vzprocps: 2.0.11-2
    vzquota: 3.0.11-1
    pve-qemu-kvm: 0.14.0-3
    ksm-control-daemon: 1.0-5"

    Still get this error:

    "VM 101 start failed: command '/usr/bin/kvm -monitor unix:/var/run/qemu-server/101.mon,server,nowait -vnc unix:/var/run/qemu-server/101.vnc,password -pidfile /var/run/qemu-server/101.pid -daemonize -usbdevice tablet -name Server2008 -smp sockets=4,cores=5 -nodefaults -boot menu=on -vga cirrus -tdf -localtime -rtc-td-hack -k en-us -drive file=/var/lib/vz/images/101/vm-101-disk-1.raw,if=ide,index=0,cache=none,boot=on -drive file=/var/lib/vz/template/iso/server2008.iso,if=ide,index=2,media=cdrom -m 64000 -netdev type=tap,id=vlan0d0,ifname=tap101i0d0,script=/var/lib/qemu-server/bridge-vlan -device rtl8139,mac=2A:56:D4:36:39:B2,netdev=vlan0d0 -id 101 -cpuunits 1000' failed with exit code 1"
     
  6. dietmar

    dietmar Proxmox Staff Member
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    Seems to be a KVM bug. Already tested wit kernel 2.6.35?
     
  7. ymmot04

    ymmot04 Member

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    I have not. I'll give it a try Tuesday and let you know the results.
     
  8. ymmot04

    ymmot04 Member

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    Updated to 2.6.35 and now the virtual machine will start with 4 sockets and 12 cores if I manually enter it in the configuration. Thanks for the help guys!

    Any idea whether the 16 socket limitation is going to be removed from the gui?
     
  9. dietmar

    dietmar Proxmox Staff Member
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    We will remove that in V2.0
     
  10. spirit

    spirit Well-Known Member
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    you can change it in:

    /usr/share/pve-manager/root/qemu/index.htm

    my $maxcpus = 48;


    (i have also a r815 ;)
     

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