Article ID: 113864, created on May 11, 2012, last review on Apr 30, 2014

  • Applies to:
  • Virtuozzo hypervisor
Synopsis:          New Parallels Server Bare Metal 5.0 kernel provides
                   an update with security and stability fixes.
Issue date:        2012-05-11
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 2.6.32-042stab055.10.


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



The current update for the Parallels Server Bare Metal 5.0 kernel provides a
new kernel based on the Red Hat 6.2 kernel (2.6.32-220.13.1.el6). The updated
kernel includes a number of security and stability fixes.



This update contains fixes for the following issues:

* Several leaks of the "kmemsize" resource under certain circumstances have
  been fixed. (PSBM-11885)

* The "fork bomb" attack protection has been enhanced. (PSBM-11920)

* An invalid NAT rules configuration on a Node with a bridge could lead to a
  kernel panic. (PSBM-11782)

* In rare cases, restoring a previously check-pointed Container could lead
  to a kernel panic if a dead task got into the Container's image. (PCLIN-30811)

* An online migration of a Container could fail with the following error message:
  "Failed to restore mount point: dev 'none', type 'devtmpfs', path '/dev'".
  This fix required changes to be made to the checkpoint image structure; so
  online migration from the current kernel (2.6.32-042stab055.10) to older kernels
  is not possible. (PCLIN-30804)

* "tcpdump" inside a host-routed Container could fail to show incoming traffic.

* The RAID1/RAID10 resync recover process could cause a Hardware Node deadlock.

* The OOM killer could fail to kill processes on a highly overcommitted
  Hardware Node. (PSBM-12523)

* A second online migration of a Container with the tun device inside could fail.

* An online migration of a Container with the running X server inside could fail
  under certain circumstances. (PSBM-12617)

* The old MegaCLI monitoring and configuration tool could cause data corruption
  and, consequently, lead to a kernel panic. (OVZ 2240)

* The memory reclaimer algorithm has been enhanced to handle writebacks
  more efficiently under high memory pressure. (PSBM-11683, OVZ 2188)

* The second value in /proc/uptime (idle time in seconds) has been virtualized.
  Previously, the Virtuozzo kernel showed idle time of the Hardware Node instead
  of that of a Container. (PCLIN-30774)

* The number of sleeping processes in /proc/vz/stats was always reported as 0.

* The sysinfo() call has been virtualized. Now it reports properly the following
  information inside a Container: uptime, load averages, and the number of
  current processes. (OVZ 2051)

* The sync() system call executed from inside a Container has been modified to
  sync only filesystems that belong to this Container.
  In particular, this fix speeds up the process of stopping Containers.

* A Hardware Node soft lockup on inode_lock spinlock triggered by the vzquota
  code has been fixed. (PCLIN-30858, OVZ 2255)



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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