Tag: debugging

Who Should Install This Hotfix?

This is a hotfix for customers running Citrix Hypervisor 8.0.

Information About this Hotfix

Issues Resolved In This Hotfix

This hotfix resolves the following issues:

• After live migration, a Windows VM can hang for over a minute.
• If you run your Windows VMs with the viridian_reference_tsc flag enabled, the VM might crash during migration.

This hotfix also allows for the following improvement:

• You can now increase the performance of Windows VMs by enabling the viridian_reference_tsc and viridian_stimer flags.

  Any new VMs created after you install this hotfix have these flags enabled by default and benefit from the performance improvement. To get the benefit of the improved performance in your existing VMs, complete the steps in the After installing this hotfix section of this article.

This hotfix also includes the following previously released hotfixes:

• CTX250041 – Hotfix XS80E001 – For Citrix Hypervisor 8.0

Installing the Hotfix

Customers should use either XenCenter or the Citrix Hypervisor Command Line Interface (CLI) to apply this hotfix. As with any software update, back up your data before applying this update. Citrix recommends updating all hosts within a pool sequentially. Upgrading of hosts should be scheduled to minimize the amount of time the pool runs in a “mixed state” where some hosts are upgraded and some are not. Running a mixed pool of updated and non-updated hosts for general operation is not supported.

Note: The attachment to this article is a zip file. It contains the hotfix update package only. Click the following link to download the source code for any modified open source components XS80E003-sources.iso. The source code is not necessary for hotfix installation: it is provided to fulfill licensing obligations.

Installing the Hotfix by using XenCenter

Choose an Installation Mechanism

There are three mechanisms to install a hotfix:

1. Automated Updates
2. Download update from Citrix
3. Select update or Supplemental pack from disk

The Automated Updates feature is available for Citrix Hypervisor Premium Edition customers, or to those who have access to XenServer through their Citrix Virtual Apps and Desktops entitlement. For information about installing a hotfix using the Automated Updates feature, see the Applying Automated Updates in the Citrix Hypervisor documentation.

For information about installing a hotfix using the Download update from Citrix option, see Applying an Update to a Pool in the Citrix Hypervisor documentation.

The following section contains instructions on option (3) installing a hotfix that you have downloaded to disk:

1. Download the hotfix to a known location on a computer that has XenCenter installed.
2. Unzip the hotfix zip file and extract the .iso file
3. In XenCenter, on the Tools menu, select Install Update. This displays the Install Update wizard.
4. Read the information displayed on the Before You Start page and click Next to start the wizard.
5. Click Browse to locate the iso file, select XS80E003.iso and then click Open.
6. Click Next.
7. Select the pool or hosts you wish to apply the hotfix to, and then click Next.
8. The Install Update wizard performs a number of update prechecks, including the space available on the hosts, to ensure that the pool is in a valid configuration state. The wizard also checks whether the hosts need to be rebooted after the update is applied and displays the result.

Follow the on-screen recommendations to resolve any update prechecks that have failed. If you want XenCenter to automatically resolve all failed prechecks, click Resolve All. When the prechecks have been resolved, click Next.

9. Choose the Update Mode. Review the information displayed on the screen and select an appropriate mode.

Note: If you click Cancel at this stage, the Install Update wizard reverts the changes and removes the update file from the host.

10. Click Install update to proceed with the installation. The Install Update wizard shows the progress of the update, displaying the major operations that XenCenter performs while updating each host in the pool.
11. When the update is applied, click Finish to close the wizard.
12. If you chose to carry out the post-update tasks, do so now.

Installing the Hotfix by using the xe Command Line Interface

1. Download the hotfix file to a known location.
2. Extract the .iso file from the zip.
3. Upload the .iso file to the Pool Master by entering the following commands:
   
   (Where -s is the Pool Master’s IP address or DNS name.)
   

   xe -s <server> -u <username> -pw <password> update-upload file-name=<filename>XS80E003.iso

   Citrix Hypervisor assigns the update file a UUID which this command prints. Note the UUID.

   b99a5e83-e335-431a-a1d1-10e222bc4bfa

4. Apply the update to all hosts in the pool, specifying the UUID of the update:

   xe update-pool-apply uuid=b99a5e83-e335-431a-a1d1-10e222bc4bfa

   Alternatively, if you need to update and restart hosts in a rolling manner, you can apply the update file to an individual host by running the following:

   xe update-apply host=<host> uuid=b99a5e83-e335-431a-a1d1-10e222bc4bfa

5. Verify that the update was applied by using the update-list command.

   xe update-list -s <server> -u root -pw <password> name-label=XS80E003

   If the update is successful, the hosts field contains the UUIDs of the hosts to which this update was successfully applied. This should be a complete list of all hosts in the pool.

6. If the hotfix is applied successfully, restart each host in the pool, starting with the master.
7. Use the update-pool-clean command to remove the update files from all hosts in the pool. This command frees up space on shared storage and does not uninstall the update.

   xe update-pool-clean uuid=b99a5e83-e335-431a-a1d1-10e222bc4bfa

After installing this hotfix

This hotfix includes updates to VM templates. These updates automatically apply to any VMs you create after applying the hotfix. To apply the updates to your existing Windows VMs and benefit from the performance improvements provided in this hotfix, complete the following steps:

1. List all VMs that use viridian:

   xe vm-list platform:viridian=true –minimal

2. For each of the VMs that you want to update:
   1. Refer to the viridian flags in the updated template for the VM. For example:

      xe template-list name-label=’Windows 7 (64-bit)’ params=platform

   2. Update the viridian flags in the platform field to match the updated template. For example:

      xe vm-param-set uuid=<vm-uuid> platform:viridian=true platform:viridian_time_ref_count=true platform:viridian_reference_tsc=true platform:viridian_apic_assist=true platform:viridian_crash_ctl=true platform:viridian_stimer=true

      Note: Only the viridian_reference_tsc and viridian_stimer flags are required to benefit from the performance improvements in this hotfix, but we advise that you set all available viridian flags.

   3. Shut down the VM.

      Do not restart the VM. The restart function does not apply these updates. Ensure that you fully shut down your VM.

      If you do not shut down your VM, you can introduce inconsistency in your viridian flags. This inconsistency can prevent you from applying further hotfixes to the Citrix Hypervisor server that hosts this VM or updating the Citrix Hypervisor server that hosts this VM to a later version.

   4. Start the VM.

Note: You can update all VMs that use viridian with a single command:

xe vm-list platform:viridian=true –minimal | tr , ‘n’ | xargs -n 1 -I {} xe vm-param-set uuid={} platform:viridian=true platform:viridian_time_ref_count=true platform:viridian_reference_tsc=true platform:viridian_apic_assist=true platform:viridian_crash_ctl=true platform:viridian_stimer=true

Only use this command if you want to update all of your VMs. You must shut down and start the VMs again for the updates to take effect.

This process does not update the snapshots associated with these VMs. Do not attempt to update existing snapshots. Instead create a new snapshot from your updated VM.

If you use your VMs with Citrix Virtual Apps and Desktops Machine Creation Services or Citrix Provisioning, ensure that you update your golden images.

Files

Hotfix File

Files Updated

More Information

For more information, see Citrix Hypervisor Documentation.

If you experience any difficulties, contact Citrix Technical Support.