Article ID: 115069, created on Oct 31, 2012, last review on May 11, 2014

  • Applies to:
  • Virtuozzo hypervisor 5.0
Synopsis:          New Parallels Server Bare Metal 5.0 kernel provides an update with security and stability fixes.
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 2.6.32-042stab063.2.


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 6.3 kernel
(2.6.32-279.11.1.el6). The updated kernel includes a number of security and
stability fixes.



This update contains fixes for the following issues:

* The Container backup (via the "vzbackup" utility) and migration processes
  restriction algorithm has been enhanced. Now if the backup/migration I/O is
  limited by the VZ_TOOLS_IOLIMIT parameter in the global "/etc/vz/vz.conf"
  configuration file), the data read from disk by the backup/migration process
  is not stored in the cache, allowing a more efficient use of the Hardware
  Node RAM. (PSBM-15797)

* The kernel process scheduler has been enhanced to run the processes of a
  Container on no more than the number of virtual CPUs assigned to the
  Container. Containers with a CPULIMIT set may gain an additional performance
  boost if they also have the CPUS parameter configured, especially if run on
  a Node with NUMA support. (PSBM-14332)

* The processes throttling algorithm (due to Container CPULIMIT restraints)
  has been improved to throttle tasks only when switching to userspace,
  increasing the overall Node performance. (PSBM-15441)

* The Node "load average" value no longer includes tasks that are throttled
  due to Container IOLIMIT/IOPSLIMIT restraints.

* A new sysctl "vm.strict_mem_cpuset" has been introduced ("0" by default).
  If this sysctl is set to "0," memory masks work as a hint. This means that if
  memory allocation from the allowed NUMA nodes fails, mask constraints are
  ignored. (PSBM-15613)

* A 32-bit Container running on a 64-bit Node could fail to load more than
  approximately 2,000 iptables rules. (PCLIN-31246)

* CPU flags were reported empty in a Container residing on a Node with a single
  physical CPU. In particular, this could affect the "yum" operation. (OVZ 2373)

* The netlink messages handling code has been fixed by setting the proper
  environment context. In particular, this fixes the network configuration
  using the Network Manager. (OVZ 2353, OVZ 2354)

* Online migration of Containers between the Nodes with the IPv6 kernel module
  unloaded or disabled could fail. (PSBM-15431)

* A memory leak issue in the checkpointing code has been fixed. (PSBM-15373)

* A kernel conditional BUG() in n_tty_read() has been removed. (OVZ 2381)

* The NFS remote locks handling in the checkpointing code has been fixed.

* Under certain circumstances, a Container with an NFS volume inside could
  fail to stop. Another symptom of this issue was the kernel work queue
  (rpciod) running in the "D" state permanently. (PSBM-15630)

* A Container with an NFS volume mounted inside could fail to stop if
  it was recently migrated from another Hardware Node using the online
  migration type. (PCLIN-31282)

* The "oom_score_adj" value has been adjusted for the "init" process to be
  killed after all other processes in a Container. (PSBM-15718)

* Under certain circumstances, the OOM killer in a Container could be triggered
  too early if the Container constantly "touched" a lot of files. (PCLIN-31294)

* The "drbd" driver has been updated to version 8.3.13. (OVZ 2254)



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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