Parallels Virtualization and Automation Software

RESOLUTION

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Synopsis: New Parallels Virtuozzo Containers 4.0 kernel provides
important fix for online migration and some other stability
fixes.
Issue date: 2008-06-17
Product: Parallels Virtuozzo Containers 4.0
Keywords: online migration fix, stability fixes
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This document provides information on the new Virtuozzo Containers 4.0 kernel,
version 2.6.18-028stab053.17.

(c) Parallels, 2008. All rights reserved.

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TABLE OF CONTENTS

1. About This Release
2. Updates Description
3. Bugs Fixed
4. Obtaining New Kernel
5. Installing New Kernel
6. Required RPMs

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1. ABOUT THIS RELEASE

The current update for the Virtuozzo Containers 4.0 kernel provides a new kernel
that includes an important fix for Containers online migration from Hardware
Nodes running Virtuozzo 3.0 to Hardware Nodes having Virtuozzo Containers 4.0
installed. This update also includes a number of other stability fixes.

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2. UPDATES DESCRIPTION

The updated Virtuozzo Containers 4.0 kernel includes fixes for the following
issues:

- A kernel crash may occur during the Containers online migration from Nodes
running Virtuozzo 3.0 to Nodes with Virtuozzo Containers 4.0 if the stateful
firewall functionality is available inside a Container.

- A kernel crash may occur during the Containers online migration from Nodes
running Virtuozzo 3.0 to Nodes with Virtuozzo Containers 4.0 due to the fact
the size of network packets control blocks in the Virtuozzo 3.0 kernel differs
from that in the Virtuozzo Containers 4.0 kernel.

- A kernel crash may occur if a Container tries to use more buffers for UDP
packets than is allowed by the 'othersockbuf' parameter.

- A kernel crash may occur under a heavy I/O load on a NFS partition if the
precise dcache accounting is enabled on the Hardware Node.

Besides, the new Virtuozzo Containers 4.0 kernel includes the following
improvement:

- The checkpointing code has been enhanced to save/restore connection marks
during the online migration (used by the 'ipt_connmark' module).

- SLM error messages have been enhanced to provide more useful information
in the event of a kernel crash if SLM detects data inconsistency during
the online migration.

We highly recommend that all Parallels Virtuozzo Containers 4.0 users update
their kernel to the latest version.

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3. BUGS FIXED

The following bugs from the previous release have been fixed in the new
Virtuozzo Containers 4.0 kernel:

- #113290: [CPT]: An incorrect ip_conntrack structure conversion during the
online migration from 2.6.9-x kernel to 2.6.18-x kernel.

- #111370: The size of packet control block depends on the availability of
IPv6 code in kernel.

- #112170: Double free for UDP socket on the error handling path.

- #100503: [UBC]: Do not do preventive dentries uncharge due to NFS
dentry release specific.

- #99679: SLM error report caused by the non-empty nofork node tree on
the process exit to be enhanced.

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4. OBTAINING NEW KERNEL

You can get this kernel update in one of the following ways:

- You can download the update from ftp://downloads.swsoft.com.

- You can download and install the update by using the vzup2date utility
included in the Parallels Virtuozzo Containers 4.0 distribution set.

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5. INSTALLING NEW KERNEL

To install the update, you should perform the following operations:

I. Use the "rpm -ihv" command to install the new kernel and Virtuozzo modules.

# rpm -ivh vzkernel-2.6.18-028stab053.17.i686.rpm \
vzmodules-2.6.18-028stab053.17.i686.rpm
Preparing... ################################# [100%]
1:vzkernel ################################# [50%]
2:vzmodules ################################# [100%]

Please DO NOT USE the "rpm -Uhv" command to install the kernel. Otherwise,
all the kernels previously installed on your system may be removed from
the Hardware Node.

II. You can adjust your boot loader configuration file to have the new kernel
loaded by default. If you use the LILO bootloader, please do not forget to
execute the 'lilo' command to write the changes to the boot sector:

# lilo
Added Virtuozzo2 *
Added Virtuozzo1
Added linux
Added linux-up

III. Reboot your computer with the "shutdown -r now" command to boot the new
kernel.

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6. REQUIRED RPMS

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

x86 kernels:

- SMP:
vzkernel-2.6.18-028stab053.17.i686.rpm
vzmodules-2.6.18-028stab053.17.i686.rpm

- Enterprise:
vzkernel-ent-2.6.18-028stab053.17.i686.rpm
vzmodules-ent-2.6.18-028stab053.17.i686.rpm

- Enterprise with the 4GB split feature disabled:
vzkernel-PAE-2.6.18-028stab053.17.i686.rpm
vzmodules-PAE-2.6.18-028stab053.17.i686.rpm


x86_64 kernels:

- SMP:
vzkernel-2.6.18-028stab053.17.x86_64.rpm
vzmodules-2.6.18-028stab053.17.x86_64.rpm

ia64 kernel:
vzkernel-2.6.18-028stab053.17.ia64.rpm
vzmodules-2.6.18-028stab053.17.ia64.rpm