Create VDI Larger than 2TB XenApp 5.6 SP2 (5.6.102)

I’ve been setting up a new XenServer with a Mirrored 250GB volume, and a RAID 5 volume with three 2TB disks. The mirror is holding the virtual servers, and the Raid5 is to be used for snapshots and the file storage. I’ve looked for a few days now trying to find a solution to exceed the 2TB limit in the new XenServer and I finally found it here. Credit to Scott Bigliardi for this:
  1. Begin by finding the uuid of the SR:
  2. Get the volume group device name:
  3. Create the new logical volume, with a proper name:
  4. Change 3T to 4T or 5T (etc) to specify the size of your giant VDI
  5. Tell XenServer to scan the SR:

After scanning the SR, the new VDI magically appeared under the Storage tab for this SR in XenCenter.

I then gave it a name and description, and assigned it to a VM just like any other VDI.


  1. I always have to make a bunch of 2TB VDs, attach them to the VM, then sew them back together in the VM with ZFS or LVM. Which is tricky because FreeBSD is unsupported, and without Xentools you are limited to 3 attached VDs and 1 is used by the VM itself! So FreeBSD ZFS over 4TB is always an unsupported hack.

    Have you tried this in a pool with an iscsi SR? If so, which node would I run lvcreate on? On any of them? I’m kinda loathe to setup iscsi iniators on each VM.

  2. Another “work-around” I recently saw suggested in the forums was to bypass the XenServer SR and directly attach iSCSI storage to your VM. Although this would (may?) cause some headaches with regard to snapshots and/or migration.

Leave a comment

Your email address will not be published. Required fields are marked *