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  1. XenServer Org
  2. XSO-831

Interface is being throttled



    • Type: Bug
    • Status: To Do (View Workflow)
    • Priority: Major
    • Resolution: Unresolved
    • Affects Version/s: 7.2
    • Fix Version/s: None
    • Component/s: Networking
    • Labels:
    • Environment:


      After running 6.5 SP1 for about 2 years we decided to upgrade our production enviroment to 7.1 (I wasnt able to chose that version when reporting this issue) mainly because of performance improvements.

      That includes disk I/O, network I/O but also to gain advantage of the improved vm-export mechanism which should be alteast 2x faster.


      After installing the machines we created 2 pools, 5 servers in each. All the hosts have their 2 ports in a active/active LACP where the mgmt also resides. The MGMT vlan is configured as native-vlanid on the switches and everything is working out fine.

      On top of this we have created a VLAN for NFS-storage and assigned an IP, then we attached the NFS SR without any mount-options.

      We also created about 30 other VLAN's without IP's for our VM's.


      Initial tests showed that we can read and write in a VM at about 900MB/s against our NFS SR which I consider are good over 10Gb.

      Also, migrating a VM within the pool shows about the same bandwidth peaks, migrating 20-30 big VM's (All from 4Gb ram to 24Gb ram) is really fast and the peaks are even higher, I can see maximum 1100MB/s.


      But that is about it, the fun is over, doing a live VM storage-migration from host-1A in pool-A to host-1B in pool-B hows only 60MB/s over the mgmt-interface.

      I then created a new VLAN called XEN-STORAGEMIGRATION in both pools, after doing that I created a new mgmt-interface (Like I did for the NFS-storage network) on all hosts in both pools within the same /24 (no routing) and tried  to use that interface for storage-migration between the pools and guess what, performance was bumped from ~60MB/s to ~160MB/

      I then tried using the regular mgmt-interface again and it is maxing out at about ~60MB/s. To be sure it wasnt some temporarily magic I tried the XEN-STORAGEMIGRATION interface again and I max it out at about ~160MB/s again....


      Obviously there is some kind of limitation on the mgmt-interface and the bond0 since the mgmt is sitting on top of it, I cant be alone to notice this.
      I've got a Intel I350 1Gb quadport in all the machines which I moved the mgmt-interface to, but that just comes down to really really slow xen-motion within the pool since it uses the mgmt-interface per default.


      And guess what interface is used when doing backups? Per default the XAPI reports the mgmt-interface's IP which means all VM-backups are done over mgmt-interface and is maxed out at ~160MB/s.

      I really do hope this is a bug in someones brain because this isnt enterprise at all, nobody will pay for XenServer if it isnt even able to max out 10Gb.





            Unassigned Unassigned
            nikade Niklas Ahden
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