| 6.2 Release NotesRelease Notes for Red Hat Enterprise Linux 6.2Edition 2 Legal NoticeCopyright © 2011 Red Hat, Inc. 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
Daftar IsiAbstractRed Hat Enterprise Linux minor releases are an aggregation of individual enhancement, security and bug fix errata. The Red Hat Enterprise Linux 6.2 Release Notes documents the major changes made to the Red Hat Enterprise Linux 6 operating system and its accompanying applications for this minor release. Detailed notes on all changes in this minor release are available in the Technical Notes. The Release Notes provide high level coverage of the improvements and additions that have been implemented in Red Hat Enterprise Linux 6.2. For detailed documentation on all changes to Red Hat Enterprise Linux for the 6.2 update, refer to the Technical Notes. Refer to the Online Release Notes for the most up-to-date version of the Red Hat Enterprise Linux 6.2 Release Notes. Chapter 1. Hardware SupportTo decompress an image, use the xz -d command. For example: ~]# xz -dc initrd.img | cpio -id To compress an image, use the xz -9 --format=lzma command. For example: ~]# find . | cpio -c -o | xz -9 --format=lzma > initrd.img <IPv6 address> [/<prefix length>]
An example of a valid IPv6 address would then be 3ffe:ffff:0:1::1/128 . If the prefix is omitted, the value of 64 is assumed. Specifying a static IPv6 address for the ipv6 boot option complements the already existing dhcp and auto parameters that can be specified for the ipv6 boot option. The kernel shipped in Red Hat Enterprise Linux 6.2 includes several hundred bug fixes for, and enhancements to, the Linux kernel. For details concerning every bug fixed and every enhancement added to the kernel for this release, refer to the kernel section of the Red Hat Enterprise Linux 6.2 Technical Notes.This new feature is enabled by default. The qla4xxx iSCSI firmware settings are accessible via: ~]# iscsiadm -m fw This feature may be disabled by setting the module ql4xdisablesysfsboot=1 parameter as follows: Set the parameter in the /etc/modprobe.d file: ~]# echo "options qla4xxx ql4xdisablesysfsboot=1" >> /etc/modprobe.d/qla4xxx.conf Reload the qla4xxx module either by executing the following set of commands: ~]# rmmod qla4xxx ~]# modprobe qla4xxx or, if you are booted off the qla4xxx device, by rebooting your system.
When booted off a qla4xxx device, upgrading from Red Hat Enterprise Linux 6.1 to Red Hat Enterprise Linux 6.2 will cause the system to fail to boot up with the new kernel. For more information on this known issue, refer to the Technical Notes. Btrfs (Note that this file system is a Technology Preview) XFS (Note that XFS is a layer product and must be installed to enable this feature)
The coretemp previously only provided per core temperatures, while the pkgtemp module provided the temperatures of the CPU package. In Red Hat Enterprise Linux 6.2, the coretemp module allows you to read the temperatures of the cores, the uncore, and the package. It is advisable to adjust any scripts using either of these modules. This is a backport of the upstream SCSI lock pushdown commit. The backport retains binary compatibility with Red Hat Enterprise Linux 6.0 and Red Hat Enterprise Linux 6.1. Retaining binary compatibility requires divergence from the equivalent upstream SCSI lock pushdown mechanism. A previously unused flag in the scsi_host_template structure is used by SCSI drivers to indicate to the SCSI midlayer that driver queuecommand will be dispatched without the SCSI host bus lock held. The default behavior is that the Scsi_Host lock will be held during a driver queuecommand dispatch. Setting the scsi_host_template lockless bit prior to scsi_host_alloc will cause the driver queuecommand function to be dispatched without the Scsi_Host lock being held. In such a case, the responsibility for any lock protection required is pushed down into the driver queuecommand code path. SCSI Drivers updated to use lockless queuecommand in Red Hat Enterprise Linux 6.2 are listed below: This feature uses the new SCSI target layer, which falls under this Technology Preview, and should not be used independently from the FCoE target support. This package contains the AGPL license. Support for af_iucv HiperSockets transport Support for forced signal adapter indications Support for asynchronous delivery of storage blocks New Ethernet Protocol ID added to the if_ether module
CTR mode for DES and 3DES XTS mode for AES with key lengths of 128 and 256 bits GHASH message digest for GCM mode ata_piix IDE-mode SATA driver Processes which are about to exit are preferred by the OOM killer. The OOM kill process also kills the children of the selected processes. A heuristic has been added to kill the forkbomb processes.
The oom_score_adj /proc tunable parameter adds the value stored in each process's oom_score_adj variable, which can be adjusted via /proc . This allows for an adjustment of each process's attractiveness to the OOM killer in user space; setting it to -1000 will disable OOM kills entirely, while setting it to +1000 marks this process as OOM's primary kill target. Added handling of /proc/sys/kernel/kptr_restrict Added more cache-miss percentage printouts Added the -d -d and -d -d -d options to show more CPU events Added the --sync/-S option Added support for the PERF_TYPE_RAW parameter Added more documentation about the -f/--fields option The python-perf package has been added for python binding support. The system calls of mremap, mincore, and mprotect /proc tunable parameters: /proc/<pid>/smaps and /proc/vmstat
Additionally, Transparent Huge Pages add some compaction improvements. If you require the old vmcore full size core file, specify the following in the /etc/kdump.conf file: core_collector /usr/bin/scp Chapter 4. Resource ManagementHowever there are enterprise scenarios listed below, where giving more than the desired CPU share to a task group is not acceptable: - Pay-per-use
In enterprise systems that cater to multiple customers, cloud service providers need to assign a fixed amount of CPU time to the virtual guest based on the service level. - Service level guarantees
Customer demands a percentage of CPU resource without service interruptions for each virtual guest.
In these scenarios, the scheduler needs to put a hard stop on the CPU resource consumption of a task group if it exceeds a preset limit. This is usually achieved by throttling the task group when it fully consumes its allocated CPU time. The cgroups CPU ceiling enforcement is considered a very important addition to the Red Hat Enterprise Linux feature repertoire, for the use case listed above. The CPU ceiling enforcement is provided by the Credit Scheduler in Xen, and also in the VMware ESX scheduler. In addition to the scalability improvement, a /proc tunable parameter, dd sysctl_sched_shares_window , has been added, with the default set to 10 ms. Chapter 5. Device DriversThe lpfc driver for Emulex Fibre Channel Host Bus Adapters has been updated to version 8.3.5.45.2p. The mptfusion driver has been updated to version 3.4.19. The bnx2fc for the Broadcom Netxtreme II 57712 chip has been updated to version of 1.0.4. The qla2xxx driver for QLogic Fibre Channel HBAs has been updated to version 8.03.07.05.06.2-k. The megaraid driver has been updated to version 5.38. The arcmsr driver for Areca RAID controllers has been updated. The beiscsi driver has been updated to version 2.103.298.0. The ipr driver for IBM Power Linux RAID SCSI HBAs has been updated to version 2.5.2. The cciss driver has been updated to provide a fix for cciss driver kdump failures. The hpsa driver has been updated to provide a fix for hpsa driver kdump failures. The bnx2i driver for Broadcom NetXtreme II iSCSI has been updated to version 2.7.0.3 to support the 578xx family of Multi-Port Single-Chip 10G Ethernet Converged Controllers. The mpt2sas driver has been updated to version 09.101.00.00. The Brocade BFA FC SCSI driver ( bfa driver) has been updated to version 2.3.2.4. The be2iscsi driver for ServerEngines BladeEngine 2 Open iSCSI devices has been updated to version 4.0.160r. The ata_generic driver has been updated to add Intel IDE-R ATA support. The isci driver has been updated to version 2.6.40-rc. The libfc , libfcoe , and fcoe drivers have been updated. The qib driver TrueScale HCAs has been updated. The libata module has been updated to include improved error handling. The md driver has been updated to include dm-raid target, which provides improved RAID capabilities through a DM interface. The dm-raid code is currently marked as a Technology Preview. Device Mapper support has been updated to upstream version 3.1+. Application support for the qla4xxx using bsg/netlink interfaces has been added. The DIF/DIX kernel code has been updated to the latest upstream version, affecting scsi , block , and dm / md .
The netxen driver for NetXen Multi port (1/10) Gigabit Network has been updated to version 4.0.75. The vmxnet3 driver has been updated. The bnx2x driver has been updated to version 1.70. The be2net driver for ServerEngines BladeEngine2 10Gbps network devices has been updated to version 4.0.100u. The ixgbevf driver has been updated to version 2.1.0-k The cxgb4 driver for Chelsio Terminator4 10G Unified Wire Network Controllers has been updated. The cxgb3 driver for the Chelsio T3 Family of network devices has been updated. The ixgbe driver for Intel 10 Gigabit PCI Express network devices has been updated to version 3.4.8-k. The e1000e driver for Intel PRO/1000 network devices has been updated to version 1.3.16-k. The e1000 driver for Intel PRO/1000 network devices has been updated, providing support for Marvell Alaska M88E1118R PHY. The e100 driver has been updated. The enic driver for Cisco 10G Ethernet devices has been updated to version 2.1.1.24. The igbvf driver has been updated to version 2.0.0-k. The igb driver for Intel Gigabit Ethernet Adapters has been updated. The bnx2 driver for the NetXtreme II 1 Gigabit Ethernet controllers has been updated to version 2.1.6+. The tg3 driver for Broadcom Tigon3 Ethernet devices has been updated to version 3.119. The qlcnic driver for the HP NC-Series QLogic 10 Gigabit Server Adapters has been updated to version 5.0.16+. The bna driver has been updated. The r8169 driver has been updated to fix two bugs related to Rx checksum offloading. The qlge driver has been updated to version v1.00.00.29. The cnic driver has been updated to add iSCSI and FCoE support for the 578xx family of Multi-Port Single-Chip 10G Ethernet Converged Controllers, VLAN support, and the new bnx2x firmware interface. The iwl6000 and iwlwifi have been updated to the EEPROM version 0x423.
The Radeon driver has been updated with post-3.0 fixes, including backported DRM and AGP code. The Nouveau and i915 drivers have been updated, including backported DRM and AGP code. The Ricoh memory stick driver ( R5C592 ) has been updated with the new KFIFO application programming interface. The Netjet driver has been updated to blacklist the Digium TDM400P PCI Card. The lm78 driver has been updated. The Wacom driver has been updated to add support for the Cintiq 21UX2, Intuos4 WL, and DTU-2231 adapter cards. The Synaptics driver has been updated to add multi-touch support. The ALSA HDA audio driver has been updated to enable or improve support for new chipsets and HDA audio codecs. The EDAC driver has been updated to support the new Northbridge chip for AMD platforms.
It is possible to create RAID logical volumes by specifying the --type <segtype> argument. The following are a few examples: Create a RAID1 array (this is a different implementation of RAID1 than LVM's mirror segment type): ~]# lvcreate --type raid1 -m 1 -L 1G -n my_lv my_vg Create a RAID5 array (3 stripes + 1 implicit parity): ~]# lvcreate --type raid5 -i 3 -L 1G -n my_lv my_vg Create a RAID6 array (3 stripes + 2 implicit parity): ~]# lvcreate --type raid6 -i 3 -L 1G -n my_lv my_vg
The XFS implementation has been improved to better handle metadata intensive workloads. An example of this type of workload is accessing thousands of small files in a directory. Prior to this enhancement, metadata processing could cause a bottleneck and lead to degraded performance. To address this problem an option to delay the logging of the metadata has been added that provides a significant performance improvement. As a result of this delayed logging of metadata, XFS performance is on par with ext4 for such workloads. The default mount options have also been updated to use delayed logging. pNFS supports 3 different storage protocols or layouts: files, objects and blocks. The Red Hat Enterprise Linux 6.2 NFS client supports the files layout protocol. To automatically enable the pNFS functionality, create the /etc/modprobe.d/dist-nfsv41.conf file with the following line and reboot the system: alias nfs-layouttype4-1 nfs_layout_nfsv41_files Now when the -o minorversion=1 mount option is specified, and the server is pNFS-enabled, the pNFS client code is automatically enabled. The system call sendmmsg socket API looks like this: struct mmsghdr {struct msghdrmsg_hdr;unsignedmsg_len; };ssize_t sendmmsg(int socket, struct mmsghdr *datagrams, int vlen, int flags); Chapter 9. Authentication and InteroperabilityThe Identity Management Guide provides detailed information about the Identity Management solution, the technologies with which it works, and some of the terminology used to describe it. It also provides high-level design information for both the client and server components. Chapter 11. Security, Standards and CertificationChapter 12. Compiler and ToolsSystemTap in Red Hat Enterprise Linux 6.2 is updated to version 1.6, providing: Kernel modules with a hyphen (" - ") in their name, such as i2c-core are now handled properly. process.mark now supports $$parms for reading probe parameters. Improved and simplified operation of the SystemTap compile-server and client: compile-server may cache script build results for improved performance. compile-server and client now communicate exchange version information to adjust the communication protocol accordingly and use the newest version of the server possible. Removal of deprecated tools: stap-client, stap-authorize-server-cert, stap-authorize-signing-cert, stap-find-or-start-server, and stap-find-servers.
For remote execution, the --remote USER@HOST functionality can now be specified multiple times and will automatically build the script for distinct kernel and architecture configurations, and run it on all named machines at once. The staprun utility now allows multiple instances of the same script to be run at the same time.
Clustered Samba (more specifically CTDB) provides the ability for the metadata to span multiple physical hosts in a cluster. CTDB will automatically recover and repair node-specific databases in case of node failures. It also provides high availability features like node monitoring and failover. Consequently, Red Hat Enterprise Linux 6.2 includes a feature (as a Technology Preview) that forces the following requirements: rgmanager must refuse to start if it sees the <rm disabled="1"> flag in /etc/cluster.conf . rgmanager must stop any resources and exit if the <rm disabled="1"> flag appears in /etc/cluster.conf during a reconfiguration.
Chapter 14. High AvailabilityRole-based access control (RBAC): enables fine-grained access levels by defining user classes to access specific cluster operations. Improved response times for destructive operations in a cluster.
Chapter 15. Virtualization- Virtual CPU timeslice sharing
Virtual CPU timeslice sharing is a performance enhancing feature at the Linux scheduler level, where an idle virtual CPU can hand the remainder of its timeslice to another virtual CPU before yielding the CPU. This feature addresses an inherent lock holder preemption issue that exists in SMP systems, that can affect performance in virtual CPUs. This feature provides stable performance in multi-processor guests. This feature is supported on both Intel and AMD processors, and is called Pause Loop Exiting (PLE) on Intel processors, and Pause Filter on AMD processors.
- Improved small message KVM performance
Red Hat Enterprise Linux 6.2 improves the KVM small message performance to satisfy a variety of networking workloads that generate small messages (< 4K). - Wire speed requirement in KVM network drivers
Virtualization and cloud products that run networking work loads need to run wire speeds. Up until Red Hat Enterprise Linux 6.1, the only way to reach wire speed on a 10 GB Ethernet NIC with a lower CPU utilization was to use PCI device assignment (passthrough), which limits other features like memory overcommit and guest migration The macvtap/ vhost zero-copy capabilities allows the user to use those features when high performance is required. This feature improves performance for any Red Hat Enterprise Linux 6.x guest in the VEPA use case. This feature is introduced as a Technology Preview. - UDP checksum optimization for KVM network drivers
UDP checksum optimization eliminates the need for the guest to validate the checksum if it has been validated by host NICs. This feature speeds up UDP external-to-guest traffic on 10 GB Ethernet cards with Red Hat Enterprise Linux 6.2 guests and hosts. The UDP checksum optimization is implemented in the virtio-net driver. - Improved I/O path performance when host slower than guest
The Red Hat Enterprise Linux 6.2 KVM network driver has improved I/O path performance, with reduced virtual machine exits and interrupts, that results in faster data delivery. This improvement enables you to run a faster guest on a slower host, without incurring any performance penalties. This enhancement is achieved by an enhanced virtio ring structure, and event index support in virtio and vhost-net .
- System monitoring via SNMP
This feature provides KVM support for a stable technology that is already used in data center with bare metal systems. SNMP is the standard for monitoring and is extremely well understood as well as computationally efficient. System monitoring via SNMP in Red Hat Enterprise Linux 6.2 allows the KVM hosts to send SNMP traps on events so that hypervisor events can be communicated to the user via standard SNMP protocol. This feature is provided through the addition of a new package: libvirt-snmp. This feature is introduced as a Technology Preview. - Improved guest debugging capabilities
Users who virtualize their data centers need a way of debugging when a guest OS becomes unresponsive and a crash dump has to be initiated. There are two methods heavily used with physical systems: Triggering a non-maskable interrupt (NMI) in the guest Sending SysRq sequences to the guest
While these capabilities are provided directly with the KVM console, a number of users use KVM through the libvirt API and virsh, where these two features were missing. Red Hat Enterprise Linux 6.2 improves guest debugging capabilities across the KVM stack, thus allowing a user to trigger NMIs in guests and send SysRq key sequences to guests. - Improve virtual machine boot up access
Users who virtualize their data centers need to track the guest boot up process and display the entire BIOS and kernel boot up message from the start. The absence of this feature prevents users from an interactive use of the virsh console, prior to boot up. A new package, sgabios, has been be added to Red Hat Enterprise Linux 6.2, to provide this capability, along with some additions to qemu-kvm. - Multi-processor (NUMA) Tuning Improvements
Red Hat Enterprise Linux 6.2 adds tuning improvements to the libvirt API stack, resulting in improved out-of-the-box performance when performing SPECvirt measurements. Red Hat Enterprise Linux 6.2 is now able to pin the memory associated with a NUMA node when a virtual machine is created. - USB enhancements
The USB 2.0 emulation has been implemented for qemu-kvm. This is available for QEMU directly only. Libvirt support is planned for the next release. Remote Wakeup support has been added for the USB host controller. Together with the cooperation of the guest OS it allows the stopping of the frequent 1000hz polling mode and putting the device to sleep. It dramatically improves the power utilization and the CPU consumption of virtual machines with a USB mouse emulation (or a tablet) - one of the common devices that every virtual machine has.
- Memory ballooning
Memory ballooning is now supported by Red Hat Enterprise Linux 6 paravirtualized Xen guests. - Domain memory limit
Memory limit for x86_64 domU PV guests has been increased to 128 GB: CONFIG_XEN_MAX_DOMAIN_MEMORY=128 . - Time accounting
The xen_sched_clock implementation (which returns the number of unstolen nanoseconds) has been replaced by the xen_clocksource_read implementation.
Support for volume change Support for async guest I/O writes and interrupts Support for suspend (S3) related guest I/O writes Support for an interrupt indicating a guest bug
[main]...installonlypkgs=rhev-hypervisor This option needs to also include the default list of installonly packages which can be found in the yum.conf man page ( man yum.conf 5 ) in the installonlypkgs option section. The X server shipped in Red Hat Enterprise Linux 6.2 has been updated to the upstream X.org 1.10 X server and the upstream Mesa 7.11 releases. The X server had internal structure changes that required updating all video and input drivers. In addition, the kernel graphics support has been updated to include new hardware support and bug fixes. The Composite extension is now functional when Xinerama is used to span a single desktop across multiple GPUs. X server configuration may now be managed with configuration file snippets under /etc/X11/xorg.conf.d/ in addition to /etc/X11/xorg.conf itself. X.org input device configuration in these snippets applies when the device becomes available to the X server at runtime. Chapter 17. General UpdatesMore flexible configuration with a new syntax. Out-ouf-process plugins (plugins run in separate processes and communicate via inter-process communication with other processes). Advantages of such a design are: bugs in plugins do not break the main daemon, more secure as most of the processing is now done under the normal (non-root) user, plugins can be written in any programming language.
Reporting backend is shared across all of Red Hat's issue reporting tools: ABRT, sealert, all users of python-meh ( Anaconda, firstboot) Because all of the tools above share the same configuration, it only has to be written once.
This appendix is a list of components and their versions in the Red Hat Enterprise Linux 6.2 release. Table A.1. Component Versions | |
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| | | | | ql23xx-firmware-3.03.27-3.1 ql2100-firmware-1.19.38-3.1 ql2200-firmware-2.02.08-3.1 ql2400-firmware-5.06.01-1 ql2500-firmware-5.06.01-1 | | | | | | | | | | |
Revision History |
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Revision 2-22.33 | 2012-08-07 | Anthony Towns | | Revision 1-0 | Tue Dec 6 2011 | Martin Prpič | Release of the Red Hat Enterprise Linux 6.2 Release Notes |
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