Issued:

2009-09-02

Updated:

2009-09-02

RHBA-2009:1422 - ktune bug fix update

Synopsis

ktune bug fix update

Type/Severity

Bug Fix Advisory

Topic

An updated ktune package that fixes a bug is now available.

Description

The ktune package includes settings for server performance-tuning.

This updated ktune package fixes the following bug:

• when running a Red Hat Enterprise Linux KVM guest under heavy load, the guest's system clock had the tendency to drift by an amount correlated with the system load. This ktune update provides an interactive Bourne shell script, fix_clock_drift.sh, which, when run as the superuser, inspects various system parameters to determine if the guest on which it is run is susceptible to clock drift under load and, if so, then creates a new "grub.conf.kvm" file in the /boot/grub/ directory. This file contains a kernel boot line with additional kernel parameters that allow the kernel to account for and prevent significant clock drift on the KVM guest. Note also that the ntpd service must be running on the KVM guest for the clock drift to be corrected.

Important: after running fix_clock_drift.sh as the superuser, and once the script has created the "grub.conf.kvm" file, then the guest's current "grub.conf" file should be backed up manually by the system administrator, the new "grub.conf.kvm" file should be manually inspected to ensure that it is identical to "grub.conf" with the exception of the additional boot line parameters, the "grub.conf.kvm" file should finally be renamed "grub.conf", and the guest should be rebooted. (BZ#518039)

Users of Red Hat Enterprise Linux KVM guests that are affected by significant clock drift are advised to upgrade to this updated package, which resolves this issue.

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 This content is not included.http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

Updated Packages

• ktune-0.2-4.el5_4.3.src.rpm
• ktune-0.2-4.el5_4.3.noarch.rpm

Fixes

• This content is not included.BZ - 518039

CVEs

(none)

References

(none)

Additional information

• The Red Hat security contact is This content is not included.secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.
• Offline Security Data data is available for integration with other systems. See Offline Security Data API to get started.