I’ve come across an issue at a customers site when creating a vdisk version within Citrix Provisioning Services. Booting a device into the maintenance disk version produced nothing but a no servers available for disk error message.  Promoting the vdisk to test allowed the device to boot as expected. I’ve not come across this particular issue before but the basic make up of the PVS environment is 2 PVS 7 servers using a single site but with the vdisk residing on local disk on the PVS servers. The PVS servers are booting from a BDM iso. Replication of the vdisk is taken care of by way of a robocopy script.

From testing out various methods of getting around this issue I came upon the following fix which hopefully might help others out too.

1/ Edit the registry of both PVS servers and add the following dword value

“HKLM\Software\Citrix\ProvisioningServices\SkipRIMSForPrivate” with the value of “1”

2/ Disable load balancing of the vdisk and manually specify the server where the maintenance disk version resides by right clicking on the vdisk in the PVS console and choosing the load balancing menu and then selecting the correct server from the “Use this server to provide this disk” option.

3/ Replicate new maintenance disk to the other PVS server by using the robocopy script so that the replication status of the disk shows as OK. The replication script can be found here.

Once I’d made these changes then the vdisk booted as expected and I could update the maintenance disk without receiving the “no servers available for disk” message.

 

Author: Dale Scriven

 

4 Responses to No servers available for disk when in maintenance mode in Citrix Provisioning Services 7

  1. Harry says:

    This is a workaround but we need a fix. Copying the vdisk to other provisioning servers is time-consuming. We normally make changes to vdisk in private mode on one provisioning server only. There may be several changes made to the same vdisk requiring reboots. Using your workaround we would have to copy the 50GB image afresh after each reboot. Only after the image is put back into standard mode do we copy it to the other provisioning servers again.

    • admin says:

      What version of provisioning services do you have as I would highly recommend migrating to PVS 7 and above and then using versioning to update your disks with. Using versioning with this issue means that a robocopy script will only copy the delta vhd so will take very little time at all. However saying that yes it is a workaround and I agree a fix is needed although I have not checked and more recent version of PVS to see if the issue is fixed. Its on a very long list of things I need to play with 🙂

  2. Avi says:

    This issue still exists in PVS 7.6, and citrix writes the following in their eDOCS

    http://support.citrix.com/proddocs/topic/provisioning-7/pvs-ha-option-intro.html

    Technologies
    Provisioning ServicesProvisioning Services 7.xProvisioning Services Administration
    Managing for Highly Available Implementations
    Provisioning Server Failover

    Updated: 2013-05-09

    By default, all Provisioning Servers within a site that can access a vDisk can provide that vDisk to target devices. Multiple Provisioning Servers can access the same physical files located on shared storage, which allows a target device to establish a connection on an alternate Provisioning Server if the connection to the active Provisioning Server is interrupted for any reason. A target device does not experience any disruption in service or loss of data when failover occurs.
    Note: For implementations that use vDisk replication, if a server failover occurs, only those servers with access to an identical replicated vDisk can provide that vDisk to target devices. For example; if vDisk is replicated across three servers hard drives and then one of the vDisks is updated, that vDisk is no longer identical and will not be considered if a server failover occurs. Even if the same exact update is made to two of the vDisks, the timestamps on each will differ, therefore the vDisks are no longer identical.
    Note: Provisioning Services does not support the high availability of vDisks on local storage that are in Private Image mode or that are currently in maintenance (read/write enabled).
    If load balancing is enabled for the vDisk and a server providing that vDisk should fail, Provisioning Services automatically balances the target device load between the remaining servers. If the load balancing option is not enabled, a single server is assigned to provide the vDisk to target devices, therefore failover will not occur.

  3. Avi says:

    just a small note on what i would expect to happen, i would expect the AVHD for the maintenance to be on only 1 pvs server since on 1 target device can access it for writing and i would expect the load balancing feature to redirect the target device to the PVS server that holds the maintenance VHD, simple as that.

    what you would end up with is working from inside the console only w/o having to do external manual copies.

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