Product Documentation

Updating Managed Servers

Apr 08, 2015

Updates to XenServer can be delivered as a Hotfix or a Service Pack. Hotfixes generally supply bug fixes to one or more specific issues; whereas Service Packs contain accumulated bug fixes, and occasionally, feature improvements and enhancements. You must pay careful attention to the Release Note that is published with each update. Each update may have unique installation instructions, particularly with regard to preparatory and post-update operations.

Attention: Before you apply an update to your hosts, you should pay careful attention to the following:
  1. Back up your data before applying an update, just as you would with any other maintenance operations. For backup procedures, see the XenServer Administrator's Guide.
  2. It is recommended that you reboot all your hosts prior to installing an update and then verify their configuration, for example, to check that VMs start and that storage is accessible. This is because some configuration changes will only take effect when a host is rebooted, so the reboot may uncover configuration problems that could cause the update to fail.
  3. When you are upgrading a pool of XenServer hosts to a newer version, you must upgrade each host in a pool and ensure that the pool is up and running before applying any hotfixes or updates.
  4. Update ALL hosts in a pool within a short period: running a mixed-mode pool (a pool that includes updated and non-updated hosts) is not a supported configuration. This should be scheduled to minimize the amount of time that a pool runs in a mixed state.
  5. Update all hosts within a pool sequentially, always starting with the pool master.
  6. After applying an update to all hosts in a pool, you should update any required driver disks before rebooting the XenServer hosts.

Applying updates to your managed servers

The Install Update wizard allows you to apply the same update to multiple hosts at the same time. The wizard automatically:

  1. migrates VMs off each host
  2. places the host in Maintenance mode
  3. applies the update
  4. reboots the host if required, and then
  5. migrate the VMs back to the updated host again

Any actions that were taken at the pre-check stage to enable the updates to be applied, such as turning off HA, will be reverted.

This section provides instructions on applying updates automatically using the Download and Install option. This option extracts the update file, opens the Install Update wizard with relevant servers selected.

If you prefer to manually download the update file and apply the update using the Install Update wizard, refer to the section To manually download and apply the updates.

  1. From the XenCenter navigation pane, click Notifications and then Updates. This provides a list of available updates.
    • By default, XenCenter periodically checks for XenServer and XenCenter updates. Click Refresh to manually check for available updates.
    • Along with other updates, the Updates view also lists any available new versions of XenServer. See Upgrading Managed Servers for information on upgrading your XenServer hosts using the Rolling Pool Upgrade wizard.
  2. From the Updates list, select the required update and click Download and Install. This extracts the update and opens the Install Update wizard on the Select Servers page with the relevant servers selected. If you would like to make any changes to the pool or the hosts being updated, clear the check boxes. Any hosts or pools that cannot be updated will be greyed out.
    Important: Citrix strongly recommends that customers read the release note published with each update. To open the release note in your browser, click the Download and Install drop-down list and then select Go to Web Page.
  3. Review the server selection and click Next to continue.
  4. The Install Update wizard performs checks to ensure there is sufficient space to upload the update. If there is enough space, the wizard successfully completes the upload. If there is insufficient space to upload the update, an error will be displayed:
    • To free up required space, if there are any residual hotfix update files remaining on the host that can be deleted, the wizard offers to clean up these files. Click Clean up to review your options and remove the files. Note that this action does not uninstall hotfixes.
    • If the Install Update wizard cannot free up the space required for the upload, you must manually delete files on your host. Click More Info for details and take necessary action to free up the required space.
  5. The Install Update wizard performs a number of update prechecks, including the space available on the hosts, to verify that the update can be applied on the selected servers 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.
  6. Click Next.
  7. 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.
  8. 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
  9. When the update has been applied, click Finish to close the Install Update wizard.
  10. If you chose to carry out the post-update tasks, do so now.

To manually download and apply the updates

XenCenter enables you to download updates to your local machine and apply the update using the Install Update wizard. To do this:

  1. From the XenCenter navigation pane, select Notifications and then Updates. This displays a list of the available XenServer and XenCenter updates.
  2. Select the required update from the list.
  3. Click the Download and Install drop-down list and then select Go to Web Page. This opens the hotfix update page in your browser.
  4. Click Download to download the file to a preferred location.
  5. From the XenCenter menu, select Tools and then Install Update.
  6. Read the information displayed on the Before You Start page and then click Next.
  7. Click Add to add the update. Browse to the location where you have saved the update file and click Open.
  8. Select the update and click Next.
  9. Select the server to which you want to apply the hotfix and then click Next.
  10. Follow the instructions from Step 4 to 10 in the section above to complete the process.