dlm-kernel bug fix update

Updated dlm-kernel packages that fix various bugs and module loading issues
are now available for Red Hat Enterprise Linux 4.6, kernel release
2.6.9-67.0.15.EL.

The dlm-kernel modules allow the Distributed Lock Manager (DLM) to
communicate with the kernel.

These updated packages fix the following bugs:

* in the previous dlm-kernel packages, dlm-kernel would panic when a
system received messages that were out of place. This may have caused
unnecessary fencing, and possibly a cluster hang. In these updated
packages, out of place messages no longer cause a panic, which resolves
this issue.

* in certain situations, the TCP Nagle algorithm caused issues with GFS
lock traffic, resulting in slow file locking on GFS nodes. In these updated
packages, this can be disabled by running the following command:

echo 1 > /proc/cluster/config/dlm/tcp_nodelay

Note: this is not a recommended default setting. On heavily used GFS
clusters, this will decrease performance dramatically.

As well, these updated dlm-kernel packages are in sync with the latest
kernel (2.6.9-67.0.15.EL). The modules in earlier dlm-kernel packages
failed to load because they did not match the running kernel. It was
possible to force load the modules; however, with this update, users no
longer need to.

Users are advised to upgrade to these latest dlm-kernel packages, which are
updated for use with the 2.6.9-67.0.15.EL kernel.

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

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/FAQ_58_10188

441758 - Intermittent Kernel Panic when attempting to add or remove a node from the cluster
442573 - flock/dlm conflict causing slow file locking on gfs nodes
442942 - Need rebuild for kernel-2.6.9-67.0.15.EL