For XenServer 5.6, Citrix and Dell have decided to retire the embedded Dell OEM XenServer edition that is usually installed on flash storage. For this release, only the hard-drive installed retail edition of XenServer is available. Customers currently running the Dell OEM edition of XenServer 5.5 or earlier can upgrade seamlessly to XenServer 5.6, preserving all of their virtual machines and configuration data.

Pre-requisites


a) XenServer 5.5

Upgrade to XenServer 5.6 is only possible from XenServer 5.5 (with or without update 1 or update 2). Customers who are running earlier OEM editions must upgrade to XenServer 5.5 OEM edition before attempting to upgrade to XenServer 5.6.

b) Backing up Virtual Machine Metadata

Citrix recommends that on any type of upgrade or update, users backup the virtual machines that are associated with the host or resource pool being upgraded or updated. The procedure for carrying out a backup is described in the XenServer Installation Guide at http://support.citrix.com/servlet/KbServlet/download/23829-102-645652/installation.pdf.

c) Hard Disk

Customers who are currently using the OEM edition of XenServer installed onto USB flash media will need to install hard disks into their systems. This change is because Retail XenServer does not support installation to USB flash media, as it does not incorporate the various disk traffic reduction measures necessary to reduce wear to the flash device.

d) 8 GB of Free Hard Disk Space

Customers using the USB flash OEM edition may have been using a hard disk in the host as a local Storage Repository (SR; used to store virtual machine disks locally). Because XenServer 5.6 must be installed to a hard disk, there must be a minimum of 8 GB of free space left on the disk (within the local SR). If there is insufficient free space, users should export one or more VMs that are stored on the local SR to other storage, before upgrading to XenServer 5.6. Users of the OEM edition who installed to hard disk (not flash) are unaffected by this space requirement, as the existing installation on the hard disk will be replaced by XenServer 5.6, and hence no extra free space is needed.

Licensing


Citrix XenServer 5.6 now uses Citrix standard licensing, and thus requires only a single web key to activate all features (instead of the dual licensing scheme used in previous versions). OEM customers who purchased Essentials for XenServer Enterprise or Platinum editions, and who installed components from the Essentials range (e.g. StorageLink, Workload Balancing, Lab Manager, Stage Manager) will be familiar with redeeming licenses from mycitrix.com and the need for a Windows-based license server to be present in their environment. These customers should return to mycitrix.com and "re-host" their existing license key in order to obtain an updated key that can be used to license XenServer 5.6. For instructions on how to re-host license keys, please see article “CTX118324 How to Return/Re-host a License using My Citrix” at http://support.citrix.com/article/ctx118324.

Customers who purchased Essentials for XenServer, but did not redeem their Essentials license key from My Citrix (using the web key provided with by their OEM) will need to locate the web key and use it at mycitrix.com. If you purchased Essentials for XenServer, but are no longer in possession of the web key, please contact your OEM to be issued with a new key.

A licensing server is required to enable the Advanced, Enterprise or Platinum features of XenServer. You can download the Citrix Licensing Server from mycitrix.com, and find documentation on its use at http://support.citrix.com/proddocs/topic/licensing-1161/lic-licensing-1161.html

Customers using the free edition of XenServer are unaffected by the new licensing requirements. Upgrade to the free edition of XenServer 5.6 can take place without deploying a license server. While upgrade to XenServer 5.6 is possible without first preparing a license server, Citrix recommends that customers deploy a license server first, in order to avoid license-enabled features of XenServer 5.6 becoming disabled when no license is found. For further details on licensing, including how to assign a license to a newly upgraded XenServer host, please see the XenServer 5.6 Installation Guide.

Upgrade Procedure

Having first ensured that the pre-requisites above are satisfied, customers should complete the following steps:

  • Download XenCenter 5.6 and install it onto a suitable client machine. The new version of XenCenter is suitable for managing older versions of XenServer, and hence no functionality will be lost.
  • Download the XenServer 5.6 installation ISO, and burn it to CD.
  • Insert the CD into the host that is to be upgraded.
  • From XenCenter, shut down or migrate all virtual machines away from the host. Once this is complete, reboot the XenServer host.
  • At the console of the host, enter the BIOS setup utility, and check that the local hard disk is included in the list of devices the host should attempt to boot from. If it is not listed, add it.
  • Boot from the XenServer 5.6 installation CD. Follow the on-screen prompts. When asked whether you wish to upgrade or re-install, choose to upgrade.
  • Follow the on-screen prompts. The installer will check for the required 8 GB of free hard disk space, and adjust the size of the local SR accordingly (assuming sufficient free space exists in it).
  • Once installation is complete, remove the installation CD from the drive.
  • If you were previously running XenServer from USB flash media, remove the flash device. This will have been set to not be bootable by the installer, and can be re-purposed.
  • Reboot the host. XenServer 5.6 will start.

Potential Issues



Citrix has thoroughly tested the upgrade from the OEM editions to XenServer 5.6. Any problems that customers experience during upgrade are likely to be due to one of the following issues:

  • Installer fails with insufficient space error: flash edition customers should ensure that at least 8 GB of free space is available on the local SR that is on the hard disk in the host. This can be achieved by exporting VMs off the host to other storage (or deleting VMs).
  • Host does not boot into XenServer following upgrade: this is most likely to be due to the hard disk not being present in the list of boot devices configured in the host's BIOS. Customers should ensure that the USB flash device is removed from the boot list, and that the hard disk is added to the list, if it is not already present. The USB flash device should also be physically unplugged from the host.