[sles-beta] Kernel and Xen changes in SLES 12 SP2

[Michal Svec]

Dear Beta Tester,

With SLES 12 SP2 there has been a notable change we would like to point 
out specifically during the Beta process.

The Xen hypervisor functions have been ported over to the standard PV-OPS 
mechanism and are now included in the default kernel. Therefore there is 
no separate kernel-xen package and binary as everything is provided by the 
default kernel.

The main purpose and benefit of this change is to have a single binary to 
cover complete functionality. This simplifies maintenance and management 
of the kernel, while also ensuring the kernel is more thoroughly tested. 
We have tested this kernel change extensively - in particular in the 
directly affected areas, but with the vast hardware and software 
combinations our customers use we wanted to point this out so that any 
potential corner cases are caught during the Beta phase.

Below are more details about this change:

AVAILABILITY
The changes have been implemented and are available in SLES 12 SP2 Beta 1.

USER-VISIBLE CHANGES
Replacing kernel-xen with kernel-default means that you cannot rely on 
`uname -r` to determine whether or not you are running under a Xen 
hypervisor (for example, in a dom0 environment). If you have any scripts 
or tooling which perform this check, we recommend replacing the uname 
check with a test for the existence of /proc/xen/privcmd (which only 
exists in a Xen dom0 environment), or test an xl command, such as `xl 
info`.

The pvops-based frontend block driver names devices using the 'xvd*' 
syntax. This naming syntax is used even if the VM configuration references 
devices using 'hd*' or 'sd*' syntax. This should not cause a problem with 
new VM installations, but when upgrading a VM to SLES 12 SP2, it may be 
necessary to manually change the name of the block devices in such places 
as /etc/fstab and /etc/default/grub. Referencing devices using UUID names 
should also avoid problems

UPGRADE PROCESS
The upgrade from SLES 11 or SLES 12 GA/SP1 follows the usual process and 
does not require anything special.

KNOWN ISSUES
We are not aware of any major bugs or issues.


Thanks in advance for all your testing

           Your SUSE Linux Enterprise Team