Installation guide

Maintenance Procedures

B.4.2. Performing a rolling pool upgrade

The correct sequence for upgrading a pool of XenServer installations to a newer version is as

follows:

1. Eject any CDs from your Virtual Machines before starting the rolling upgrade. Having CDs

inserted during rolling upgrade can prevent migrations from working correctly, and due to

the mode of operation of the pool whilst the rolling upgrade is taking place, it is required that

this be done before the rolling upgrade is started.

2. Upgrade your XenCenter to the latest version. The newer version will continue to operate

fine against older versions of XenServer hosts.

3. Verify that there are no VMs in the Suspended state. This is indicated in XenCenter by a blue

paused icon. Importantly, any suspended virtual machine with a CD drive attached (with the

Tools ISO or a local physical drive, for example) will not be resumable after upgrade. To get

the virtual machine back into a usable state, one would have to perform a "Force Shutdown"

of the suspended VM.

4. Migrate all VMs running on the pool master to other XenServer Hosts using XenMotion. The

pool master is identified in XenCenter as being the topmost server in the pool, and shows

Server type: Master in the General tab when selected.

5. Shut down the pool master using XenCenter or the command line interface. This will cause

your pool to enter emergency mode. VMs will continue to run, but you will be unable to

perform control operations. This is expected behavior.

6. Boot the pool master using your XenServer installation media or network and follow the in-

structions for doing a standard installation and upgrade (see Chapter 3, Installing XenServ-

er).

7. On restarting your pool master, after a few minutes your pool will leave emergency mode

and normal service will be restored.

8. You are now ready to upgrade a second XenServer Host. You should select a XenServer

Host still running an old version of XenServer and migrate the VMs running on this XenServer

Host to the one you have just upgraded. Do not attempt to migrate a VM from an upgraded

XenServer Host to one that has not yet been upgraded. You will see an error message if

you attempt to do this, and your VM will continue running without being migrated.

9. Upgrade the member XenServer Host you have just freed up following a similar procedure

as for the master; shut down the member using XenCenter or the command line interface

(your pool will not enter emergency mode this time), then upgrade the server software using

your product media or remote installation repository.

10. Repeat the previous two steps for each member XenServer Host in the pool.

11. Now that you have upgraded the XenServer Host software on your pool, it is important to

upgrade the XenServer Tools in each VM. This will enable new functionality and ensure

the stability of your VMs. Running old versions of XenServer Tools on newer XenServer

installations is not a supported configuration except for during the upgrade process. Please

refer to the XenCenter Help, or the XenServer Virtual Machine Installation Guide for details

on how to perform the upgrade of XenServer Tools for Windows and Linux VMs.

B.5. Upgrading from version 3.2 to 4.0.1