- Issued:
- 2008-07-25
- Updated:
- 2008-07-25
RHBA-2008:0796 - Bug Fix Advisory
Synopsis
dlm-kernel bug fix update
Type/Severity
Bug Fix Advisory
Topic
Updated dlm-kernel packages that fix various bugs and module-loading issues
are now available for Red Hat Enterprise Linux 4.7, kernel release
2.6.9-78.EL.
Description
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, which may have occurred
when adding or removing nodes. 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, the TCP Nagle algorithm 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.
Also, these updated dlm-kernel packages are in sync with the latest
kernel (2.6.9-78.EL). The modules in earlier dlm-kernel packages fail to
load because they do not match the running kernel. It is possible to
force-load the modules; however, with this update, force-loading the
modules is not required.
Users are advised to upgrade to these latest dlm-kernel packages, which are
updated for use with the 2.6.9-78.EL kernel.
Solution
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
Affected Products
- Red Hat Enterprise Linux High Availability for x86_64 4 x86_64
- Red Hat Enterprise Linux High Availability for x86_64 4 ppc
- Red Hat Enterprise Linux High Availability for x86_64 4 ia64
- Red Hat Enterprise Linux High Availability for x86_64 4 i386
Fixes
- BZ - 244708 - flock/dlm conflict causing slow file locking on gfs nodes
- BZ - 427531 - Intermittent Kernel Panic when attempting to add or remove a node from the cluster
CVEs
(none)
References
(none)
The Red Hat security contact is secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.