6.1 Release Notes

[이누기]

 출처: http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/96/html-single/6.1_Release_Notes/index.html

6.1 Release Notes

Release Notes for Red Hat Enterprise Linux 6.1 Beta

Logo

Legal Notice

Copyright © 2011 Red Hat.

The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at http://creativecommons.org/licenses/by-sa/3.0/. In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version.

Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law.

Red Hat, Red Hat Enterprise Linux, the Shadowman logo, JBoss, MetaMatrix, Fedora, the Infinity Logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries.

Linux? is the registered trademark of Linus Torvalds in the United States and other countries.

Java? is a registered trademark of Oracle and/or its affiliates.

XFS? is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries.

MySQL? is a registered trademark of MySQL AB in the United States, the European Union and other countries.

All other trademarks are the property of their respective owners.

1801 Varsity Drive

 Raleigh, NC 27606-2072 USA

 Phone: +1 919 754 3700

 Phone: 888 733 4281

 Fax: +1 919 754 3701

Abstract

The Beta Release Notes provide an overview of the major new features and enhancements in Red Hat Enterprise Linux 6.1 Beta.

Note: The Release Notes document a pre-release version of Red Hat Enterprise Linux 6.1. The included information is subject to substantial change, and is provided only as a preview. The included instructions should not be considered complete, and should be used with caution.

1. Hardware Support 2. Kernel 3. Desktop 4. Storage 5. Authentication and Interoperability 6. Security 7. Installation 8. Compiler and Tools 9. Clustering 10. Virtualization 11. Entitlement 12. General Updates A. Technology Previews B. Known Issues 

 B.1. Installer B.2. Deployment B.3. Virtualization B.4. Storage and Filesystems B.5. Networking B.6. Clustering B.7. Authentication B.8. Devices B.9. Kernel B.10. Desktop

 C. Revision History

1. Hardware Support

1.1. Naming convention for network interfaces 1.2. CPU and Memory Hot-add 1.3. Driver Updates

1.1. Naming convention for network interfaces

Traditionally, network interfaces in Linux are named eth[X]. However, in many cases, these names do not correspond to actual labels on the chassis. Modern server platforms with multiple network adapters can encounter non-deterministic and counterintuitive naming of these network interfaces.

Red Hat Enterprise Linux 6.1 introduces biosdevname, an optional convention for naming network interfaces. biosdevname assigns names to network interfaces based on their physical location.

Note

In Red Hat Enterprise Linux 6.1 Beta, biosdevname is disabled by default, except for a limited set of the latest Dell systems.

Refer to the Red Hat Knowledge Base for further information on using biosdevname.

1.2. CPU and Memory Hot-add

On Nehalem-EX, full hot-adding of CPUs and memory is now fully supported in Red Hat Enterprise Linux 6.1

1.3. Driver Updates

Red Hat Enterprise Linux 6.1 features a wide range of driver updates, including updates to the following device drivers:

ixgbe driver for Intel 10 Gigabit PCI Express Network devices

mlx4 driver for Mellanox ConnectX HCA InfiniBand hardware, providing support for Mellanox Connect X2/X3 10GB devices

be2net driver for ServerEngines BladeEngine2 10Gbps network devices

bnx2 driver for Broadcom NetXtreme II network devices, including support for Advanced Error Reporting (AER), and PPC support for 5709 devices

bnx2i driver for Broadcom NetXtreme II iSCSI

bnx2x driver for Broadcom Everest network devices

igbvf and ixgbevf Virtual Function drivers

e1000e driver for Intel PRO/1000 ethernet devices

tg3 driver for Broadcom Tigon3 ethernet devices

bfa driver for Brocade Fibre Channel to PCIe Host Bus Adapters

bna driver for Brocade 10G PCIe Ethernet Controllers

cxgb4 driver for Chelsio Terminator4 10G Unified Wire Network controllers

be2iscsi driver for ServerEngines BladeEngine 2 Open iSCSI devices

be2net driver for ServerEngines BladeEngine2 10Gbps network devices

lpfc driver for Emulex Fibre Channel HBAs

e1000 and e1000e drivers for Intel PRO/1000 network devices

Intel Iron Pond Ethernet driver

Intel Kelsey Peak Wireless driver

megaraid_sas driver for LSI MegaRAID SAS controllers

2. Kernel

2.1. Scheduler 2.2. Performance updates and improvements 2.3. Networking updates 2.4. kdump

Control Groups

Control groups are a new feature of the Linux kernel introduced in Red Hat Enterprise Linux 6. Each control group is a set of tasks on a system that have been grouped together to better manage their interaction with system hardware. Control groups can be tracked to monitor the system resources that they use. Additionally, system administrators can use control group infrastructure to allow or to deny specific control groups access to system resources such as memory, CPUs (or groups of CPUs), networking, I/O, or the scheduler.

Updates to Control Groups in Red Hat Enterprise Linux 6.1 include:

Added control group ability to throttle block device I/O to a particular device, either bytes per second or Input/Output Operations Per Second (IOPS)

Allow the creation of Hierarchical block device control groups, providing the ability to easily integrate with libvirt and other userspace

The new block device control group tunable group_idle, providing better throughput with control groups while maintaining fairness

The new autogroup feature to reduce latencies, for more interactive tasks during CPU intensive workloads

the new cgsnapshot tool provides the ability to take a snapshot of the current control group configuration

Note

Control Groups and other resource management features are discussed in detail in the Red Hat Enterprise Linux 6 Resource Management Guide

2.1. Scheduler

A process (or task) scheduler is a specific kernel subsystem that is responsible for assigning the order in which processes are sent to the CPU.

Scheduler updates include:

optimize CPU scheduling algorithms by making better decisions on which CPU's processes should run on based on the system NUMA topology

fix undesirable side effects of tickless timer

several optimizations that prevents load balancing from occuring too often.

more use of RCU locking in the scheduler for better concurrent processing.

and many more optimizations and improvements

2.2. Performance updates and improvements

Numerous updates and improvements to VM and Transparent Huge Page support

Perf_event updates, and add perf lock feature for better way to analyze lock events

Add ftrace events, such as wakeup latency tracer, to graph tracer: more insight into maximum latency for a task to get scheduled after wakeup, and trace of functions called during that time

Introduce kprobes jump optimization to reduce overhead and enhance SystemTap performance

i7300_edac, i7core_edac update supports monitoring of memory errors on motherboards using intel 7300 chipset

2.3. Networking updates

Receive Packet Steering (RPS) breaks the bottleneck of having to receive network traffic for a NIC on one CPU

Receive Flow Steering (RFS) allows the optimal CPU to receive network data intended for a specific application

Add getsockopt support for TCP thin-streams to reduce latency from retransmission of lost packets in time-sensitive applications

Add Transparent Proxy (TProxy) support for non-locally bound IPv4 TCP and UDP sockets (similar to Linux 2.2)

2.4. kdump

kdump is an advanced crash dumping mechanism. When enabled, the system is booted from the context of another kernel. This second kernel reserves a small amount of memory, and its only purpose is to capture the core dump image in case the system crashes.

In Red Hat Enterprise Linux 6.1 introduces the kernel message dumper, which is called when a kernel panic occurs. The kernel message dumper provides easier crash analysis and allows 3rd party kernel message logging to alternative targets.

Additionally, the crashkernel=auto parameter syntax is removed. The default parameter syntax is now crashkernel=:[@offset].

3. Desktop

Graphics Hardware

Red Hat Enterprise Linux 6.1 Beta provides a range of updates for graphics hardware, most notably:

The new driver for Intel Generation 6 Graphics integrated into the Sandy Bridge processor provides full accelerated 2D and 3D graphics

Added support for the Matrox MGA-G200ER graphics chipset

An increased default resolution (1024 x 768 pixels) on monitors that do not supply Extended Display Identification Data (EDID)

Network Manager

NetworkManager is the desktop tool that is used to set up, configure and manage a wide range of network connection types. In Red Hat Enterprise Linux 6.1, NetworkManager has improved support for the configuration of Wi-Fi Protected Access (WPA) Enterprise and Internet Protocol version 6 (IPv6).

4. Storage

LVM Snapshots of Mirrors

The LVM snapshot feature provides the ability to create backup images of a logical volume at a particular instant without causing a service interruption. When a change is made to the original device (the origin) after a snapshot is taken, the snapshot feature makes a copy of the changed data area as it was prior to the change so that it can reconstruct the state of the device. In Red Hat Enterprise Linux 6.1 the ability to take a snapshot of a mirrored logical volume is a fully supported feature.

LVM Stripe of Mirrors

It is now possible to combine RAID0 (striping) and RAID1 (mirroring) in a single logical volume in LVM. Creating a logical volume while simultaneously specifying the number of mirrors ('--mirrors X') and the number of stripes ('--stripes Y') results in a mirror devices whose constituent devices are striped.

5. Authentication and Interoperability

System Security Services Daemon (SSSD)

The System Security Services Daemon (SSSD) implements a set of services for central management of identity and authentication. Centralizing identity and authentication services enables local caching of identities, allowing users to still identify in cases where the connection to the server is interrupted. SSSD supports many types of identity and authentication services, including: Red Hat Directory Server, Active Directory, OpenLDAP, 389, Kerberos and LDAP. SSSD in Red Hat Enterprise Linux 6.1 Beta is updated to version 1.5, providing the following bug fixes and enhancements:

netgroups support

Improved online/offline detection

Improved LDAP access-control provider with support for shadow and authorizedService

Improved caching and cleanup logic for different schemata

Improved DNS based discovery

Automatic Kerberos ticket renewal

Enablement of the Kerberos FAST protocol

Better handling of password expiration

Password obfuscation for LDAP account

Further Reading

The Deployment Guide contains a section that describes how to install and configure SSSD.

IPA

Red Hat Enterprise Linux 6.1 Beta features IPA as a Technology Preview. IPA is an integrated security information management solution which combines Red Hat Enterprise Linux, Red Hat Directory Server, MIT Kerberos, and NTP. It provides web browser and command-line interfaces, and its numerous administration tools allow an administrator to quickly install, set up, and administer one or more servers for centralized authentication and identity management.

Samba

Samba is an open source implementation of the Common Internet File System (CIFS) protocol. It allows the networking of Microsoft Windows, Linux, UNIX, and other operating systems together, enabling access to Windows-based file and printer shares. Samba in Red Hat Enterprise Linux 6.1 Beta is updated to version 3.5.6.

Samba in Red Hat Enterprise Linux 6.1 Beta allows users to use their own Kerberos credentials when accessing CIFS mount, rather than needing same mount credentials for all access to the mount.

FreeRADIUS

FreeRADIUS is an Internet authentication daemon, which implements the RADIUS protocol, as defined in RFC 2865 (and others). It allows Network Access Servers (NAS boxes) to perform authentication for dial-up users. FreeRADIUS in Red Hat Enterprise Linux 6.1 Beta is updated to version 2.1.10.

Kerberos

Kerberos is a networked authentication system which allows users and computers to authenticate to each other with the help of a trusted third party, the KDC. In Red Hat Enterprise Linux 6.1 Beta, Kerberos (supplied by the krb5 package) is updated to version 1.9.

6. Security

OpenSCAP

OpenSCAP is a set of open source libraries that support the Security Content Automation Protocol (SCAP) standards from the National Institute of Standards and Technology (NIST). OpenSCAP supports the SCAP components:

Common Vulnerabilities and Exposures (CVE)

Common Platform Enumeration (CPE)

Common Configuration Enumeration (CCE)

Common Vulnerability Scoring System (CVSS)

Open Vulnerability and Assessment Language (OVAL)

Extensible Configuration Checklist Description Format (XCCDF)

Additionally, the openSCAP package includes an application to generate SCAP reports about system configuration. openSCAP is now a fully supported package in Red Hat Enterprise Linux 6.1.

Smartcard support for SPICE

The Simple Protocol for Independent Computing Environments (SPICE) is a remote display protocol designed for virtual environments. SPICE users can view a virtualized desktop or server from the local system or any system with network access to the server. Red Hat Enterprise Linux 6.1 introduces support for smartcard passthough via the SPICE protocol.

Further Reading

The Security Guide assists users and administrators in learning the processes and practices of securing workstations and servers against local and remote intrusion, exploitation and malicious activity.

7. Installation

Installation and boot support is added in Red Hat Enterprise Linux 6.1 Beta for the Emulex 10GbE PCI-E Gen2 and Chelsio T4 10GbE network adapters. Additionally, teh GRUB bootloaded is updated with support for booting volumes with a 4KB sector size on UEFI systems.

The installer in Red Hat Enterprise Linux 6.1 Beta will detect unsupported hardware platforms and provide a notification to the user. The installation will continue, but the following message is displayed                       This hardware (or a combination thereof) is not supported by Red Hat. For more information on supported hardware, please refer to http://www.redhat.com/hardware.

Improved support for iSCSI adapters

Red Hat Enterprise Linux 6.1 Beta features improved support for iSCSI adapters at installation and boot time, including the ability to separate login credentials for iSCSI storage during installation and support for partial offload iSCSI adapters (e.g. the Emulex Tiger Shark adapter).

Red Hat Enterprise Linux 6 supports installation over iSCSI using auto-detection of BIOS iSCSI settings in iBFT. However, reconfiguration of the iBFT settings after installation was not possible. In Red Hat enterprise Linux 6.1, TCP/IP settings and iSCSI initiator configuration are dynamically configured from iBFT settings during boot time.

8. Compiler and Tools

8.1. SystemTap 8.2. GNU Project Debugger (GDB) 8.3. OProfile 8.4. Valgrind 8.5. GNU Compiler Collection (GCC) 8.6. libdfp 8.7. Eclipse 8.8. IcedTea

8.1. SystemTap

SystemTap is a tracing and probing tool that allows users to study and monitor the activities of the operating system (particularly, the kernel) in fine detail. It provides information similar to the output of tools like netstat, ps, top, and iostat; however, SystemTap is designed to provide more filtering and analysis options for collected information.

SystemTap in Red Hat Enterprise Linux 6.1 Beta is updated to version 1.4, providing:

Alpha version of remote host scripting with --remote USER@HOST

Optimization of near zero cost for dormant user probe points

Refer to the SystemTap Release Notes for more information.

8.2. GNU Project Debugger (GDB)

The GNU Project Debugger (normally referred to as GDB) debugs programs written in C, C++, and other languages by executing them in a controlled fashion, and then printing out their data. GDB in Red Hat Enterprise Linux 6.1 Beta is updated to version 7.2, providing many bugfixes and enhancements, including enhancements to the python scripting features, and C++ debugging enhancements.

8.3. OProfile

OProfile is a system-wide profiler for Linux systems. The profiling runs transparently in the background and profile data can be collected at any time. In Red Hat Enterprise Linux 6.1 Beta, OProfile is updated to version 0.9.6-12, providing support for AMD family 12h/14h/15h processors and Intel Westmere specific events.

8.4. Valgrind

Valgrind is an instrumentation framework for building dynamic analysis tools that can be used to profile applications in detail. Valgrind tools are generally used to automatically detect many memory management and threading problems. The Valgrind suite also includes tools that allow you to build new profiling tools to suit your needs.

Red Hat Enterprise Linux 6.1 Beta provides Valgrind version 3.6.0.

8.5. GNU Compiler Collection (GCC)

The GNU Compiler Collection (GCC) includes, among others, C, C++, and Java GNU compilers and related support libraries. Red Hat Enterprise Linux 6 features version 4.4 of GCC, which includes the following features and enhancements:

IBM z196 new instruction support and optimizations

IBM z10 prefetch instruction support and optimizations

8.6. libdfp

The libdfp library is updated in Red Hat Enterprise Linux 6.1 Beta. libdfp is a decimal floating point math library, and is available as an alternative to the glibc math functions on Power and s390x architectures, and is available in the supplementary channels.

8.7. Eclipse

Eclipse is a powerful development environment that provides tools for each phase of the development process. It is integrated into a single, fully configurable user interface for ease of use, featuring a pluggable architecture which allows for extension in a variety of ways.

An updated version of the Eclipse development environment is available in Red Hat Enterprise Linux 6.1 Beta, providing the following updates and enhancements:

All the major plugins are refreshed, including Valgrind and OProfile integration and the tools for working with C and C++

The Mylyn task-focused framework is updated

Enhanced resource filtering for workspace contents

performance enhancements when working with C, C++ and Java code bases

8.8. IcedTea

New IcedTea Web Open Source Web Browser Plugin and Webstart implementation for OpenJDK.

Allows browsers such as Firefox to load Java applet‎s embedded in a web page

Provides framework to launch JNLP (Java Network Launching Protocol) files

9. Clustering

Clusters are multiple computers (nodes) working in concert to increase reliability, scalability, and availability to critical production services. High Availability using Red Hat Enterprise Linux 6 can be deployed in a variety of configurations to suit varying needs for performance, high-availability, load balancing, and file sharing.

The following major updates to clustering are available in Red Hat Enterprise Linux 6.1 Beta

The cluster resource agent for the Network File System version 4 (NFSv4) resource agent now has NFSv4 recovery support

Rgmanager now supports the concept of critical and non-critical resources

A restart recovery can now be performed without the need to relocate a service if restart fails

System Administrators can now configure and run a cluster using command line tools. This feature provides an alternative to manually editing the cluster.conf configuration file or using the graphical configuration tools (Luci and Ricci)

Red Hat Enterprise Linux High Availability on Red Hat Enterprise Linux KVM hosts is fully supported

Comprehensive SNMP Trap support from all cluster daemons and sub-parts

Additional watchdog integration allows a node to reboot itself when it loses quorum or is fenced using fence_scsi

Further Reading

The Cluster Suite Overview document provides an overview of Red Hat Cluster Suite for Red Hat Enterprise Linux 6. Additionally, the High Availability Administration document describes the configuration and management of Red Hat cluster systems for Red Hat Enterprise Linux 6.

10. Virtualization

vhost

The new host kernel networking backend, vhost, is a fully supported feature in Red Hat Enterprise Linux 6.1. vhost provides superior throughput and latency over the userspace implementation.

qcow2

The qcow2 image format now supports caching of metadata. Additionally, support is added for live snapshots using external qcow2 images.

Block I/O latency improvements

ioeventfd is now available, providing faster notification of block I/O.

Kernel SamePage Merging (KSM)

The KVM hypervisor in Red Hat Enterprise Linux 6 features Kernel SamePage Merging (KSM), allowing KVM guests to share identical memory pages. Page sharing reduces memory duplication, allowing a host with similar guest operating systems to run more efficiently.

KSM in Red Hat Enterprise Linux 6.1 is Transparent HugePage aware. KSM has the ability to scan subpages inside hugepages and split them when merging is possible.

Additionally, KSM enablement can now be controlled on a per-VM basis.

PCI device assignment improvements

PCI configuration space access is improved, enabling a broader set of PCI devices to be device-assigned to guest VMs.

KVMClock Improvements

In Red Hat Enterprise Linux 6.1, the Time Stamp Counter (TSC) synchronization can now be automatically detected on guest bootup or when a host CPU is hot-plugged. Additionally, the TSC synchronization frequency is adjusted after a live migration.

QEMU monitor

Human Monitor pass through is enabled. Additionally, the new drive_del command allows libvirt to safely remove a block device from a guest.

General Updates and Improvements

The maximum display resolution on qemu-kvm is now 2560x1600 pixels

Red Hat Enterprise Linux 6.1 Beta includes the ability to expose an emulated Intel HDA sound card to all guests. This update enables native sound support for many guests including the 64-bit version of Windows 7

QEMU char device flow control is enabled

Message Signaled Interrupts (MSI) implemented for the win-virtio-blk driver

A new standard interface for selecting/prioritizing the boot devices of the guest

Stablity improvements for live migration

QEMU userspace static tracing

Virtual disk online dynamic resize feature

Forbid pci hot unplug of critical devices such as gpu, pci bus controller, isa bus controller

11. Entitlement

Red Hat Subscription Manager and the Entitlements Platform

Effective software and infrastructure management requires a mechanism to handle the software inventory — both the type of products and the number of systems that the software is installed on. In parallel with Red Hat Enterprise Linux 6.1, Red Hat is introducing a new Entitlement Platform which provides oversight for the software entitlements for an organization and a more effective content delivery system. On local systems, the new Red Hat Subscription Manager offers both GUI and command-line tools to manage the local system and its allocated subscriptions. A better method to handle subscriptions will help our customers maintain their software compliance and will make installing and updating Red Hat products much simpler.

Further Reading

The Red Hat Enterprise Linux 6.1 Beta Deployment Guide contains further information on managing subscriptions. Additionally, the Red Hat Enterprise Linux 6.1 Beta Installation Guide contains further information on the registration and subscription process at install time

12. General Updates

Automated Bug Reporting Tool

Red Hat Enterprise Linux 6 introduced the new Automated Bug Reporting Tool (ABRT). ABRT logs details of software crashes on a local system, and provides interfaces (both graphical and command line based) to report issues to Red Hat support. In Red Hat Enterprise Linux 6.1 Beta, ABRT is updated to version 1.1.16. This update provides an enhanced graphical user interface (GUI) in addition to a range of other bugfixes and enhancements.

openCryptoki

openCryptoki contains version 2.11 of the PKCS#11 API, implemented for IBM Cryptocards. openCryptoki is updated in Red Hat Enterprise Linux 6.1 Beta, providing many bugfixes and enhancements, including better overall performance.

OpenLDAP

OpenLDAP is an open source suite the Lightweight Directory Access Protocol (LDAP) applications and development tools. OpenLDAP in Red Hat Enterprise Linux 6.1 Beta is updated to version 2.4.23. This updated version of OpenLDAP utilizes Network Security Services (NSS) cryptographic libraries, replacing OpenSSL.

TigerVNC

TigerVNC provides client and server software for Virtual Network Computing (VNC). VNC is a remote display system, allowing a user to view a computing desktop environment over a network connection.TigerVNC is updated to version 1.1.0, providing many bugfixes enhanced encryption support.

tuned

tuned is a system tuning daemon that monitors system components and dynamically tunes system settings. Utilizing ktune (the static mechanism for system tuning), tuned can monitor and tune devices (e.g. hard disk drives and ethernet devices). In Red Hat Enterprise Linux 6.1 Beta, the tuned tuning profiles now include support for the s390x architectures.

A. Technology Previews

Open Multicast Ping (Omping) 

Open Multicast Ping (Omping) is a tool to test the IP multicast functionality primarily in the local network. This utility allows users to test multicast and assists in the diagnosing if an issues is in the network configuration or elsewhere (i.e. a bug). In Red Hat Enterprise Linux 6 omping is provided as a Technology Preview.

Matahari 

Matahari provides a set of Application Programming Interfaces (APIs) for operating systems management for remote access over QMF/QPID. In Red Hat Enterprise Linux 6.1, Matahari is considered a Technology Preview feature.

System Information Gatherer and Reporter (SIGAR) 

The System Information Gatherer and Reporter (SIGAR) is a library and command-line tool for accessing operating system and hardware level information across multiple platforms and programming languages. In Red Hat Enterprise Linux 6.1 Beta, SIGAR is considered a Technology Preview package.

fsfreeze 

Red Hat Enterprise Linux 6 includes fsfreeze as a Technology Preview. fsfreeze is a new command that halts access to a filesystem on disk. fsfreeze is designed to be used with hardware RAID devices, assisting in the creation of volume snapshots. Further details on fsfreeze are in the fsfreeze(8) man page.

DIF/DIX support 

DIF/DIX, is a new addition to the SCSI Standard and a Technology Preview in Red Hat Enterprise Linux 6. DIF/DIX increases the size of the commonly used 512-byte disk block from 512 to 520 bytes, adding the Data Integrity Field (DIF). The DIF stores a checksum value for the data block that is calculated by the Host Bus Adapter (HBA) when a write occurs. The storage device then confirm‎s the checksum on receive, and stores both the data and the checksum. Conversely, when a read occurs, the checksum can be checked by the storage device, and by the receiving HBA.

The DIF/DIX hardware checksum feature must only be used with applications that exclusively issue O_DIRECT I/O. These applications may use the raw block device, or the XFS file system in O_DIRECT mode. (XFS is the only filesystem that does not fall back to buffered IO when doing certain allocation operations.) Only applications designed for use with O_DIRECT I/O and DIF/DIX hardware should enable this feature. Red Hat Enterprise Linux 6 includes the Emulex LPFC driver version 8.3.5.17, introducing support for DIF/DIX. For more information, refer to the Storage Administration Guide

Filesystem in Userspace 

Filesystem in Userspace (FUSE) allows for custom filesystems to be developed and run in user-space.

btrfs 

Btrfs is under development as a file system capable of addressing and managing more files, larger files, and larger volumes than the ext2, ext3, and ext4 file systems. Btrfs is designed to make the file system tolerant of errors, and to facilitate the detection and repair of errors when they occur. It uses checksums to ensure the validity of data and metadata, and maintains snapshots of the file system that can be used for backup or repair. The btrfs Technology Preview is only available on the x86_64 architecture.

Btrfs is still experimental

Red Hat Enterprise Linux 6 Beta includes Btrfs as a technology preview to allow you to experiment with this file system. You should not choose Btrfs for partitions that will contain valuable data or that are essential for the operation of important systems.

LVM Application Programming Interface (API) 

Red Hat Enterprise Linux 6 Beta features the new LVM application programming interface (API) as a Technology Preview. This API is used to query and control certain aspects of LVM.

FS-Cache 

FS-Cache is a new feature in Red Hat Enterprise Linux 6 Beta that enables networked file systems (e.g. NFS) to have a persistent cache of data on the client machine.

IPv6 support in IPVS 

The IPv6 support in IPVS (IP Virtual server) is considered Technology Preview.

pacemaker 

Pacemaker, a scalable high-availability cluster resource manager, is included in Red Hat Enterprise Linux 6 as a Technology Preview. Pacemaker is not fully integrated with the Red Hat cluster stack.

XFS in the Red Hat Enterprise Linux 6 High Availability Add On 

XFS in the Red Hat Enterprise Linux 6 High Availability Add On is considered Technology Preview.

upd-unicast support 

Cluster membership can now be initiated using udp-unicast (UDPU). The older protocol (multicast) is often restricted by corporate IT policy, making it difficult to deploy clusters. Introducing UDPU support alliviates that limitation. This feature is considered a Technology Preview in Red Hat Enterprise Linux 6.1.

certmonger 

The certmonger service aims to manage certificates on behalf of services running on client systems. It warns administrators when a certificate which it has been asked to watch is nearing the end of its validity period, and can be told to attempt to automatically obtain a new certificate when this happens. It supports certificates and private keys stored in either PEM or NSS database formats. It can interact with CAs running either IPA or certmaster, and is intended to be extensible to support other implementations.

TPM 

TPM hardware can create, store and use RSA keys securely (without ever being exposed in memory), verify a platform's software state using cryptographic hashes and more. The user space libraries, trousers and tpm-tools are considered a Technology Preview in this Red Hat Enterprise Linux 6.

Brocade BFA Driver 

The Brocade BFA driver is considered a Technology Preview feature in Red Hat Enterprise Linux 6. The BFA driver supports Brocade FibreChannel and FCoE mass storage adapters.

SR-IOV on the be2net driver 

The SR-IOV functionality of the Emulex be2net driver is considered a Technology Preview in Red Hat Enterprise Linux 6.

Kernel Media support (Tech Preview)  

Very current upstream video4linux

Digital video broadcasting

Primarily infrared remote control device support

Many webcam support fixes and improvements

Remote Audit Logging 

The audit package contains the user space utilities for storing and searching the audit records generated by the audit subsystem in the Linux 2.6 kernel. Within the audispd-plugins subpackage is a utility that allows for the transmission of audit events to a remote aggregating machine. This remote audit logging application, audisp-remote, is considered a Technology Preview in Red Hat Enterprise Linux 6.

Linux (NameSpace) Container [LXC] 

Linux (NameSpace) Containers [LXC] is a Technology Preview feature in Red Hat Enterprise Linux 6 Beta that provides isolation of resources assigned to one or more processes. A process is assigned a separate user permission, networking, filesystem name space from its parent.

Error Detection And Correction (EDAC) driver interface 

The Error Detection And Correction (EDAC) driver interface for processors based on the Intel microarchitecture codename Nehalem is considered a Technology Preview in this pre-release version of Red Hat Enterprise Linux 6.

B. Known Issues

B.1. Installer

In some circumstances, disks that contain a whole disk format (e.g. a LVM Physical Volume populating a whole disk) are not cleared correctly using the clearpart --initlabel kickstart command. Adding the --all switch — as in clearpart --initlabel --all — ensures disks are cleared correctly.

During the installation on POWER systems, the error messages similar to: attempt to access beyond end of device

loop0: rw=0, want=248626, limit=248624

may be returned to sys.log. The errors do not prevent installation and only occur during initial setup. The filesystem created by the installer will function correctly.

When installing on the s390x architecture, if the installation is being performed over SSH, avoid resizing the terminal window containing the SSH session. If the terminal window is resized during installation, the installer will exit and installation will terminate.

The kernel image provided on the CD/DVD is too large for Open Firmware. Consequently, on the POWER architecture, directly booting the kernel image over a network from the CD/DVD is not possible. Instead, use yaboot to boot from a network.

The anaconda partition editing interface includes a button labeled Resize. This feature is intended for users wishing to shrink an existing filesystem and underlying volume to make room for installation of the new system. Users performing manual partitioning cannot use the Resize button to change sizes of partitions as they create them. If you determine a partition needs to be larger than you initially created it, you must delete the first one in the partitioning editor and create a new one with the larger size.

Channel IDs(read, write, data) for network devices are required for defining and configuring network devices on s390 systems. However, system-config-kickstart — the graphical user interface for generating a kickstart configuration — cannot define channel IDs for a network device. To work around this issue, manually edit the kickstart configuration that system-config-kickstart generates to include the desired network devices.

B.2. Deployment

Some HP Proliant servers may report incorrect CPU frequency values in /proc/cpuinfo or /sys/device/system/cpu/*/cpufreq. This is due to the firmware manipulating the CPU frequency without providing any notification to the operating system. To avoid this ensure that the "HP Power Regulator" option in the BIOS is set to "OS Control". An alternative available on more recent systems is to set "Collaborative Power Control" to "Enabled".

B.3. Virtualization

Under some circumstances, installation of a Red Hat Enterprise Linux 6 virtual guest stalls after the optional testing of media. Note that this issue has only been observed with Red Hat Enterprise Linux 6 guests that utilize multiple virtualized CPUs. To work around this issue, use a media source that is known to be verified, and skip the media test, or use a single virtualized CPU during installation.

In earlier versions of Red Hat Enterprise Linux, libvirt permitted PCI devices to be insecurely assigned to guests. In Red Hat Enterprise Linux 6, assignment of insecure devices is disabled by default by libvirt. However, this may cause assignment of previously working devices to start failing. To enable the old, insecure setting, edit /etc/libvirt/qemu.conf, set "relaxed_acs_check = 1", and restart libvirtd. Note that this action will re-open possible security issues.

The balloon service on Windows 7 guests can only be started by the "Administrator" user.

Libvirt uses transient iptables rules for managing NAT or bridging to virtual machine guests. Any external command that reloads iptables state ( such as running system-config-firewall) will overwrite the entries needed by libvirt. Consequently, after running any command or tool that changes the state of iptables, guests may lose access the network. To work around this issue, use the command 'service libvirt reload' to restore libvirt's additional iptables rules.

KVM users with a mix of virtio and ata disks should verify the boot device that anaconda chooses during installation. To verify the boot device, locate the "Install Target Devices" list in the disk selection screen that follows the partitioning type screen. Verify the boot device selection, which is indicated by a selector in the left-most column of the "Install Target Devices" list.

A Windows virtual machine must be restarted after the installation of the kernel windows driver framework. If the virtual machine is not restarted it may crash when a memory balloon operation is performed.

A dual function, 82576 interface (codename: Kawela, PCI Vendor/Device ID: 8086:10c9) cannot have both physical functions (PF's) device-assigned to a Windows 2008 guest. Either physical function can be device assigned to a Windows 2008 guest (PCI function 0 or function 1), but not both.

virt-v2v is able to convert guests running on ESX server. A current limitation in virt-v2v means that if an ESX guest has a disk with a snapshot, the snapshot must be on the same datastore as the underlying disk storage. If the snapshot and underlying storage are on different datastores, virt-v2v will report a 404 error while trying to retrieve the storage.

B.4. Storage and Filesystems

The NFSv4 server in Red Hat Enterprise Linux 6 currently allows clients to mount using UDP and advertises NFSv4 over UDP with rpcbind. However, this configuration is not supported by Red Hat and violates the RFC 3530 standard.

If a device-mapper-multipath device is still open, but all of the attached paths have been lost, the device is unable to create a new table with no paths. Consequently, the following unusual output may be returned from the multipath -ll output command: mpatha (3600a59a0000c2fd0003079284c122fec) dm-0,

size=2.0G hwhandler='0'

|-+- policy='round-robin 0' prio=0 status=enabled

| `- #:#:#:# -   #:#  failed faulty running

`-+- policy='round-robin 0' prio=0 status=enabled

  |- #:#:#:# -   #:#  failed faulty running

  `- #:#:#:# -   #:#  failed faulty running

Output of this type indicates that there are no paths to the device. The erroneous lines in the output preceded by the string #:#:#:# will be removed in a future release.

dracut currently only supports one FiberChannel over Ethernet (FCoE) connection to be used to boot from the root device. Consequently, booting from a root device that spans multiple FCoE devices (e.g. using RAID, LVM or similar techniques) is not possible.

B.5. Networking

When configuring a network interface manually, including static IP addresses and search domains, it is possible that a search entry will not be propagated to /etc/resolv.conf. Consequently, short host names that do not include the domain name will fail to resolve. To workaround this issue, add a search entry manually to /etc/resolv.conf.

B.6. Clustering

luci will not function with Red Hat Enterprise Linux 5 clusters unless each cluster node has ricci version 0.12.2-14

B.7. Authentication

none 

B.8. Devices

Red Hat Enterprise Linux 6 only has support for the first revision of the UPEK Touchstrip fingerprint reader (USB ID 147e:2016). Attempting to use a second revision device may cause the fingerprint reader daemon to crash. The command lsusb -v -d 147e:2016 | grep bcdDevice

will return the version of the device being used in an individual machine.

The Emulex Fibre Channel/Fibre Channel-over-Ethernet (FCoE) driver in Red Hat Enterprise Linux 6 does not support DH-CHAP authentication. DH-CHAP authentication provides secure access between hosts and mass storage in Fibre-Channel and FCoE SANs in compliance with the FC-SP specification. Note, however that the Emulex driver (lpfc) does support DH-CHAP authentication on Red Hat Enterprise Linux 5, from version 5.4. Future Red Hat Enterprise Linux 6 releases may include DH-CHAP authentication.

The recommended minimum HBA firmware revision for use with the mpt2sas driver is "Phase 5 firmware" (i.e. with version number in the form 05.xx.xx.xx.) Note that following this recommendation is especially important on complex SAS configurations involving multiple SAS expanders.

B.9. Kernel

Loading the megaraid_sas driver on the kdump kernel will result in the insmod command being blocked, returning messages similar to: INFO: task insmod:201 blocked for more than 120 seconds.

Refer to BZ#682110 for more information.

In Red Hat Enterprise Linux 6.1, the nmi_watchdog registers with the perf subsystem. Consequently, during boot, the perf subsystem grabs control of the performance counter registers, blocking oprofile from working. To resolve this, either boot with the nmi_watchdog=0 kernel parameter set, or run echo 0 >/proc/sys/kernel/nmi_watchdog to disable at run time. To re-enable the watchdog, use the command echo 1 >/proc/sys/kernel/nmi_watchdog.

Due to the way ftrace works when modifying the code during startup, the NMI watchdog causes too much noise and ftrace can not find a quiet period to instrument the code. Consequently, machines with more than 512 cpus will encounter issues with the NMI watchdog. Such issues will return error messages similar to "BUG: NMI Watchdog detected LOCKUP" and have either 'ftrace_modify_code' or 'ipi_handler' in the backtrace. To work around this issue, disable nmi_watchdog using the command: nmi_watchdog=0

Creating many 'cpu' control groups (cgroups) on a system with a large number of CPUs will slow down the machine when the control groups feature is enabled. To work around this issue, disable control groups.

On 64-bit POWER systems the EHEA NIC driver will fail when attempting to dump a vmcore via NFS. To work around this issue, utilize other kdump facilities, for example dumping to the local filesystem, or dumping over SSH.

A BIOS emulated floppy disk might cause the installation or kernel boot process to hang. To avoid this, disable emulated floppy disk support in the BIOS.

The preferred method to enable nmi_watchdog on 32-bit x86 systems is to use either nmi_watchdog=2 or nmi_watchdog=lapic parameters. The parameter nmi_watchdog=1 is not supported.

The kernel parameter, pci=noioapicquirk, is required when installing the 32 bit variant of Red Hat Enterprise Linux 6 on HP xw9300 workstations. Note that the parameter change is not required when installing the 64 bit variant.

B.10. Desktop

When enabled, fingerprint authentication is the default authentication method to unlock a workstation, even if the fingerprint reader device is not accessible. However, after a 30 second wait, password authentication will become available.

Evolution's IMAP backend only refreshes folder contents under the following circumstances: when the user switches into or out of a folder, when the auto-refresh period expires, or when the user manually refreshes a folder (i.e. using the menu item Folder >Refresh). Consequently, when replying to a message in the Sent folder, the new message does not immediately appear in the Sent folder. To see the message, force a refresh using one of the methods describe above.

The clock applet‎ in the GNOME panel has a default location of Boston, USA. Additional locations are added by via the applet‎'s preferences dialog. Additionally, to change the default location, left-click the applet‎, hover over the desired location in the "Locations" section, and click the "Set..." button that appears.

In some multi-monitor configurations (e.g. dual monitors with both rotated), the cursor confinement code produces incorrect results. For example, the cursor may be permitted to disappear offscreen when it should not, or be prevented from entering some areas where it should be allowed to go. Currently, the only work around to this issue is to disable monitor rotation.

If a Russian keyboard is chosen during system installation, the login screen is configured to use Russian input for user names and passwords by default. However, pressing Left Shift and Right Shift does not cause the input to change to ASCII mode. Consequently, the user cannot log in. To work around this issue, run the following sequence, as root, post installation: . /etc/sysconfig/keyboard; echo $LAYOUT | grep -q ",us" && gconftool-2

--direct --config-source xml:readwrite:/var/lib/gdm/.gconf --set

/apps/gdm/simple-greeter/recent-layouts --type list --list-type string $(echo

$LAYOUT | awk -F, '{ print "[" $2 "," $1 "]"; }') && echo "DONE"

C. Revision History

Revision History
Revision 1-0	Tue Mar 22 2011	Ryan Lerch
Initial Release of the Red Hat Enterprise Linux 6.1 Beta Release Notes

[김동현]

이제6.1정식릴리즈되면 적극적으로 수요가 늘겠네요