Even though at some point it looked like debian lenny will not have full xen support (for the 2.6.26 amd64 kernel) in the end this was fixed and lenny supports fully Xen ever on amd64. Upgrading from 2.6.18 to 2.6.26 is very straightforward (though we were using xen-hypervisor 3.2-1 already) and the only problem noticed was that the console on the domU machines was no longer working: it was showing the output correctly, but you could not enter anything on the console.
This is caused by the ‘new Xen console’ (xen now uses hvc0 for its console) and to fix it you have to add to your virtual machine xen configuration file one line: extra = “console=hvc0 xencons=tty”, restart the vm and it should be fine. In /etc/xen/
If you are using pygrub then in grub.conf on the domU add: console=hvc0 xencons=tty to the kernel line, like:
Here are the xen packages lenny uses:
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