RHBA-2011:0342 - Bug Fix Advisory

Topic

Updated xen packages that fix various bugs are now available for Red Hat
Enterprise Linux 5 Extended Update Support.

Description

Xen is a high-performance and secure open source virtualization framework.
Virtualization allows users to run guest operating systems in virtual machines
on top of a host operating system.

This update fixes the following bugs:

• With a large number of virtual block devices (VBDs) or virtual guests,

looking for duplicate devices could take a very long time and significantly
increase overall boot time. With this update, this procedure has been optimized
not to require XenStore, so that virtual guests now boot much faster.
Additionally, this update also ensures that the domain record counter contains a
correct value when a XenStore transaction is canceled. Note that when you add a
network interface controller (NIC) with an automatically generated MAC address,
this address is not verified. Avoid using a combination of hard-coded and
automatically assigned MAC addresses, as this can lead to a guest network
failure. (BZ#666802)

• Previously, creating a new domain caused a hot plug script to perform an

additional check of disk sharing capabilities. With a large number of virtual
block devices (VBDs), this operation could take a long time, and an attempt to
create a new domain could fail due to a timeout. Since a similar checking
mechanism is already implemented in the xend service, this update removes this
algorithm from the hot plug script, so that it no longer causes a domain
creation to fail. (BZ#680928)

Users of xen are advised to upgrade to these updated packages, which resolve
these issues. Note that after installation, the xend service must be restarted
for this update to take effect.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.6 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.6 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386
• Red Hat Enterprise Linux Server - AUS 5.6 x86_64
• Red Hat Enterprise Linux Server - AUS 5.6 ia64
• Red Hat Enterprise Linux Server - AUS 5.6 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.6 i386

Fixes

• BZ - 666802 - [5.4][Xen]When many guests are created by "xm create", the boot time increases quadratically with the number of total VBDs
• BZ - 680928 - Domain creation failed when previous domains have lots of vbds

CVEs

(none)

References

(none)