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I am trialing using a distributed file system as the backend storage for my Xen Servers.

I have set up the DFS (distributed file system) (using CentOS and GlusterFS) and everything is working perfectly with suprisingly good IOPS speed, however I am now running into an issue with the VHD's (virtual hard disks) which are being synced to my planned DR (desaster recovery) storage.

My VHD's are being written to two local SAN (storage area network) servers and these are then synced using geo-replication to an offsite SAN server. I also have two xen servers connected to the offsite SAN servers.

I can see the VHD's in my offsite storage and I have found that if:

  1. I just move the VHD's into the SR (storage repository), it causes the SR to break.
  2. If I copy and rename the VHD's into the SR, the SR works fine and I can see the VHD in Xen Center, however when I try and start a VM using this VHD, Xen throws an error.

Does anyone know why this is happening and what I can do to try and fix this issue. I know I can import the VHD into XenServer using XenCenter, but I am looking for something which I can do with a script, rather than manually.


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Which xen-server version? What error do you get? SAN server sounds like iSCSI - is this correct? – Nils Dec 26 '12 at 21:36
I am running Xen Server 6.0, the SAN's are running as NFS storage shares. – boburob Dec 27 '12 at 8:29
SAN per definition is FC or iSCSI. NFS is NAS. My guess is that this is propably the root-cause of your problem. Your offsite NAS-server has propably a different NFS-filehandle. So what is your error-message? – Nils Dec 27 '12 at 14:08
Sorry, its a bit confusing to describe my setup here, storage is being supplied to two servers from a SAN, which is then utilizing it with Gluster to create a share which is replicated offsite. The main problem I am facing is to do with the VHD's which are being replicated offsite. I have found a way around this by creating a VM in the XenServer offsite and copying and replacing the VHD with one that has been synced but it feels a bit hacky to me. – boburob Dec 27 '12 at 15:07
Since I am only familiar with XEN 3 and 4 (OpenSource) can you describe that VHD-setup in more detail? What do you do to create them, how do you replicate offsite? Maybe that SR is just as inflexible as the one from Oracle-VM (based on a RedHat-clone and XEN 4 with BEA-Weblogic GUI frontend). – Nils Dec 28 '12 at 22:35

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