Article ID: 114242, created on Jun 28, 2012, last review on Apr 27, 2014

  • Applies to:
  • Virtuozzo hypervisor 5.0


Synopsis:          New Parallels Server Bare Metal 5.0 kernel provides
                   an update with security and stability fixes.
Issue date:        2012-06-29
Product:           Parallels Server Bare Metal 5.0
Keywords:          'bugfix' 'stability' 'security'


This document provides information on the new Parallels Server Bare Metal 5.0
kernel, version 2.6.32-042stab057.1.


1. About This Release
2. Updates Description
3. Obtaining New Kernel
4. Required RPMs
5. References



The current update for the Parallels Server Bare Metal 5.0 kernel provides a
new kernel based on the Red Hat Enterprise Linux 6.2 kernel
(2.6.32-220.23.1.el6).  The updated kernel includes a number of security and
stability fixes.



This update contains fixes for the following issues:

* Support for Containers based on the Fedora 17 template has been added.
  (PSBM-13010, PSBM-13004, PSBM-13213)

* The fuse context pid has been virtualized, which in particular fixes the
  behavior of the "tup" application if it is running in a Container. (OVZ 2245)

* The ext4 filesystem performance has been improved by adding the ability to
  submit large IO requests and optimize the handling of fdatasync() calls
  running in parallel. (PCLIN-30841, PSBM-12094)

* Additional sanity checks have been added to the ext4 filesystem code to
  prevent possible kernel panics if the filesystem gets corrupted. (PSBM-12241)

* Kernel BUG at block/cfq-iosched.c:386 could occur when disabling group
  isolation. (PCLIN-30890)

* The IPv6 hash table function has been enhanced, making "Neighbor table
  overflow" messages appear less often. (PCLIN-30609)

* 'vmstat' could fail with the "Floating point exception" message due to
  an incorrect idle time accounting reported via /proc/stat. (PCLIN-30773)

* The locking order in the cgroups code has been corrected to fix possible
  kernel deadlocks. (PSBM-13297)

* A corner case in the memory reclaimer has been enhanced: OOM killer is now
  guaranteed to be invoked if no progress is made in memory reclaiming.

* The initrd kernel image generation has been corrected. This affects only nodes
  running CentOS 5.x and Red Hat Enterprise Linux 5.x Host OSs. (PCLIN-30970)

* Tasks with the SCHED_IDLE or SCHED_BATCH scheduler policy set online migration
  support has been added. (OVZ 2283)

* Kernel compilation without the CONFIG_SCHEDSTATS configuration option has
  been fixed. (OVZ 2299)

* Kernel compilation without the CONFIG_BSD_PROCESS_ACCT configuration option
  has been fixed. (OVZ 2273)

* Kernel debug functionality has been enhanced:
  - Scheduler debug information has been moved from the Alt+SysRQ+t key output
    to Alt+SysRQ+a.
  - kernel.hung_task_verbosity sysctl has been added to configure additional
    debug data printing if a hanged task is detected:
	    1 sysrq-p (cpus)
	    2 sysrq-t (tasks)
	    4 sysrq-m (memory)
	    8 sysrq-a (scheduler)
	    0 default (nothing)
	   -1 anything



You can download and install this kernel update using the vzup2date utility
included in the Parallels Server Bare Metal 5.0 distribution set.



Depending on the processor installed on the Hardware Node, the following RPM
packages are included in the kernel update:




Copyright (c) 1999-2012 Parallels Holdings, Ltd. and its affiliates. All rights

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