Who should install this Hotfix XS55E004 – For XenServer 5.5?
Customers using Intel hardware with EPT support should install this Hotfix. Note that this hotfix includes and supersedes XS55E002 (CTX122348).

If customers are unable to apply this hotfix, Citrix recommends that you use the workaround available at CTX122731 – Workaround for Those Unable to Install Hotfix XS55E004.

Issues resolved in this Hotfix
This Hotfix resolves an issue where Virtual Machines (VMs) on Intel Nehalem systems may crash during migration and/or some operations are performed on the console.

Installing the Hotfix

Use XenCenter or the Command Line Interface (CLI) to install this Hotfix. You must restart the server after installing the Hotfix to ensure that it takes effect. As with any software update, back up your data before proceeding.

Always install the Hotfix to the master of your pool first. If you do not do this, updated slaves cannot reconnect to the pool until the master has also been updated. Following the steps below once to upgrade the master, restarting the master, and then following the steps again for each of the slaves is a best practice to ensure that the installation is completed in the correct order.

If you are applying the Hotfix in a pool, be aware that until the update has been installed, virtual machines might crash during migration unless you have previously applied XS55E002. This means that installing the Hotfix might require you to suspend VMs in order to reboot servers to complete the update application process, rather than migrating them to other servers as you might normally do when applying XenServer updates.

Installing the Hotfix using XenCenter:
On a computer that has XenCenter installed, download the Hotfix to a known location.

In XenCenter, on the Tools menu, and select the Install New Update menu item.

Select the servers to update.
Citrix advises you to update the Pool master first by selecting only that host for upgrade initially, then re-running the update wizard for all the slaves afterwards. You are also advised to upgrade all hosts in a pool within a short space of time. Running a mixed pool of updated and non-updated hosts for general operation is not supported.
Click Next to proceed.

Enter the path or browse to your downloaded update file.
Click Next and the update is uploaded to the pools and servers you chose to update.

Select an update mode.
Citrix strongly advises that you use Manual mode for this update. If you select Manual mode, the update is applied on each server but you must manually restart the servers for the update to take effect.
Click Next to proceed.

The system verifies that the update can be successfully applied. This can take some time. The wizard then advances to a page showing the steps that will be taken to apply the update.

Click Next to install the update.
Review the steps as they might include migration of VMs, or suspending them to disk for single hosts or cases where there is not enough free capacity in the pool, which causes service interruption.

Once the update has completed, click Finish to exit the wizard
Installing the update using the off-host CLI:
On a computer that has XenCenter installed, download the Hotfix to a known location.
Upload the patch to the pool or host you wish to apply it to:
xe –s -u root –pw patch-upload file-name=
The update identifier is printed to the screen:
1f26d321-cbd3-4721-9af5-02101cfc0136
Apply the patch to the pool specifying the Universally Unique Identifier (UUID) of the patch as given by the upload command in the previous step:
xe -s -u root -pw patch-pool-apply \
uuid=1f26d321-cbd3-4721-9af5-02101cfc0136
Restart the master of your pool and wait for it to finish booting.
Restart all remaining hosts in the pool to complete the patch installation.

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