6.3 Release Notes
Release Notes for Red Hat Enterprise Linux 6.3
Edition 3
Abstract
Preface
Important
Chapter 1. Kernel
The dm-thinp
targets, thin
and thin-pool
, provide a device-mapper device with thin-provisioning and scalable snapshot capabilities. This feature is available as a Technology Preview. For more information on the newly-introduced LVM thin provisioning, refer to Chapter 9, Storage.
The lpfc
driver is deprecating the sysfs
mbox
interface as it is no longer used by the Emulex tools. Read and write operations are now stubbed out and only return the -EPERM
(Operation not permitted) symbol.
For a complete list of supported Kdump targets (that is, targets that kdump can use to dump a vmcore to), refer to the following Kbase article: https://access.redhat.com/knowledge/articles/41534.
Red Hat Enterprise Linux 6.3 adds support for mount options to restrict access to /proc/<PID>/
directories. One of the new options is called hidepid=
and its value defines how much information about processes is provided to non-owners. The gid=
option defines a group that gathers information about all processes. Untrusted users, which are not supposed to monitor tasks in the whole system, should not be added to the group.
Support for the O_DIRECT
flag for files in FUSE (File system in Userspace) has been added. This flag minimizes cache effects of the I/O to and from a file. In general, using this flag degrades performance, but it is useful in special situations, such as when applications do their own caching.
In Red Hat Enterprise Linux 6.3, the CONFIG_STRICT_DEVMEM
configuration option is enabled by default for the PowerPC architecture. This option restricts access to the /dev/mem
device. If this option is disabled, userspace access to all memory is allowed, including kernel and userspace memory, and accidental memory (write) access could potentially be harmful.
In Red Hat Enterprise Linux 6.3, the high-resolution timer's capacity to remap the HPET registers into the memory of a user process has been enabled.
A number of patches have been applied to the kernel in Red Hat Enterprise Linux 6.3 to improve overall performance and reduce boot time on extremely large systems (patches were tested on a system with 2048 cores and 16 TB of memory).
The Intel Core i5 and i7 processors (formerly code-named Ivy Bridge) support a new rdrand
instruction to quickly generate random numbers. The kernel shipped in Red Hat Enterprise Linux 6.3 utilizes this instruction to provide quick random number generation.
Persistent storage (pstore
), a file system interface for platform dependent persistent storage, now supports UEFI.
Support for CPU family specific container files has been added. Starting with AMD family 15h processors, a container such as microcode_amd_fam15h.bin
is now loaded for the aforementioned family of processors.
Red Hat Enterprise Linux 6.3 includes full USB 3.0 support.
In Red Hat Enterprise Linux 6.3, the kdump/kexec kernel dumping mechanism is enabled for IBM System z systems as a Technology Preview, in addition to the IBM System z stand-alone and hypervisor dumping mechanism. The auto-reserve threshold is set at 4 GB; therefore, any IBM System z system with more than 4 GB of memory has the kexec/kdump mechanism enabled.
..no such file or directory
/etc/kdump.conf
, system-config-kdump, or firstboot.
The ftrace function tracer now allows modules and all users to make use of the ftrace function tracing utility. For more information, refer to the following man pages:
man trace-cmd-record man trace-cmd-stack
When tracing processes with more than one thread, the ltrace utility would neglect to trace threads other than the main thread. But because threads share address space, those other threads would still see breakpoints distributed by ltrace. Consequently, those threads would be killed by a SIGTRAP
signal. Red Hat Enterprise Linux 6.3 includes thread-awareness and breakpoint handling mechanisms. Support for tracing of multi-threaded processes is now on par with tracing single-threaded process.
Cross Memory Attach provides a mechanism to reduce the number of data copies needed for intra-node inter-process communication. In particular, this allows MPI libraries doing intra-node communication to do a single copy of the message rather than a double copy of the message via shared memory. This technique has been employed in the past through multiple, unique driver-based implementations. The implementation introduced in Red Hat Enterprise Linux 6.3 provides a general solution for this functionality. In addition, it provides a layer of abstraction for device driver writers who wish to exploit these functions without having to modify their corresponding implementations when there are changes in the memory management subsystem.
Red Hat Enterprise Linux 6.3 enhances the usage of mutexes. Additional information provided to the scheduler allows for more efficient and less costly decisions when optimizing processor cycles depending on the usage of mutexes, thread scheduling, and the status of the physical and virtual processors. The status of a thread owning a locked mutex is examined and waiting threads are not scheduled unless the first thread is scheduled on both a virtual and a physical processor.
Red Hat Enterprise Linux 6.3 enables improved diagnosis of PAV (Parallel Access Volume) and HPF (High Performance Ficon) environments to analyze and tune the DASD performance on a system, for example, to give recommendations regarding the number of alias devices or the usage of PAV versus HyperPAV.
With Red Hat Enterprise Linux 6.3, collective problem analysis through consolidated dumps of software and hardware is enabled. A command can be used to generate qeth
or qdio
trace data and to trigger the internal dump of an OSA device.
The CONFIG_VGA_SWITCHEROO
configuration option is now enabled by default to allow switching between two graphics cards.
With Red Hat Enterprise Linux 6.3, the crashkernel=auto
parameter changed the default kdump enabling threshold from 4 GB to 2 GB. This means that any machine that has 2 GB (or more) of memory will have the kdump feature enabled on its systems.
- To stop the
kdump
service, execute the following command:~]#
service kdump stop
- To disable the
kdump
service, execute the following command:~]#
chkconfig kdump off
- To return memory previously reserved for
kdump
back to the system, execute the following command:~]#
echo 0 > /sys/kernel/kexec_crash_size
Chapter 2. Device Drivers
The Brocade BFA Fibre Channel and FCoE driver is no longer a Technology Preview. In Red Hat Enterprise Linux 6.3 the BFA driver is fully supported.
The Brocade BNA driver for Brocade 10Gb PCIe ethernet Controllers is no longer a Technology Preview. In Red Hat Enterprise Linux 6.3 the BNA driver is fully supported.
The SR-IOV functionality of the Emulex be2net
driver is considered a Technology Preview in Red Hat Enterprise Linux 6.3. You must meet the following requirements to use the latest version of SR-IOV support:
- You must run the latest Emulex firmware (revision 4.1.417.0 or later).
- The server system BIOS must support the SR-IOV functionality and have virtualization support for Direct I/O VT-d.
- You must use the GA version of Red Hat Enterprise Linux 6.3.
be2net
driver software.
- Red Hat Enterprise Linux 6.3 includes the
mtip32xx
driver which adds support for Micron RealSSD P320h PCIe SSD drives. - The
lpfc
driver for Emulex Fibre Channel Host Bus Adapters has been updated to version 8.3.5.68.2p. - The
mptfusion
driver has been updated to version 3.04.20. - The
bnx2fc
for the Broadcom Netxtreme II 57712 chip has been updated to version 1.0.11. - The
qla2xxx
driver for QLogic Fibre Channel HBAs has been updated to version 8.04.00.02.06.3-k. Theqla2xxx
driver update for Red Hat Enterprise Linux 6.3 now takes advantage of the common code in the SCSI mid-layer that handles queue-full status messages returned from a target port. Before, this code resided in theqla2xxx
driver itself. To maintain API compatibility, stubs for theql2xqfulltracking
andql2xqfullrampup
module parameters have been left in the driver itself.In addition, this update also adds support for ISP82xx and ISP83xx, and adds the dynamic logging functionality. - The
qla4xxxx
has been updated to version 5.02.00.00.06.03-k1, which adds support for displayingport_state
,port_speed
, andtargetalias
in thesysfs
file system. - The
megaraid
driver has been updated to version 00.00.06.14-rh1. - The
ipr
driver for IBM Power Linux RAID SCSI HBAs has been updated to enable the SAS VRAID functions. - The
cciss
driver has been updated to add older controllers to the kdump blacklist. - The
hpsa
driver has been updated to the version 2.0.2-4 to add older controllers to the kdump blacklist. - The
bnx2i
driver for Broadcom NetXtreme II iSCSI has been updated to version 2.7.2.1. - The
mpt2sas
driver has been updated to version 12.101.00.00, adding NUNA I/O support which uses multi-reply queue support of HBAs. - The
mptsas
driver has been updated to add the following device ID:SAS1068_820XELP
. - The Brocade BFA FC SCSI driver (
bfa
driver) has been updated. - The
be2iscsi
driver for ServerEngines BladeEngine 2 Open iSCSI devices has been updated. - The
ahci.c
driver have been updated to add the AHCI-mode SATA DeviceID for the Intel DH89xxCC PCH. - The
isci
driver has been updated to version 1.1 to pick up the latest Intel hardware support, enhancements, and bug fixes. - The
isci sata
driver has been updated to add T10 DIF support. - The
libfc
,libfcoe
, andfcoe
drivers have been updated to fix various bugs and add several enhancements. - The
libsas
driver has been updated. - The
qib
driver for TrueScale HCAs has been updated. - The
libata
module has been updated to fix various bugs. - The dm-raid code of the
md
driver has been updated to include flush support. - The following drivers have been updated to the latest version:
ahci
,md
/bitmap
,raid0
,raid1
,raid10
, andraid456
. - The
aacraid
driver has been updated to version 1.1-7[28000].
- The
netxen
driver for NetXen Multi port (1/10) Gigabit Network has been updated to version 4.0.77 or greater. - The
bnx2x
driver has been updated to version 7.2.16 to include support for the 578xx family of chips. - The
be2net
driver for ServerEngines BladeEngine2 10Gbps network devices has been updated to version 4.2.5.0r. - The
ixgbevf
driver has been updated to version 2.2.0-k to include the latest hardware support, enhancements, and bug fixes. - 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 3.6.7-k to include the latest hardware support, enhancements, and bug fixes. - The
e1000e
driver for Intel PRO/1000 network devices has been updated. - The
e1000
driver for Intel PRO/1000 network devices has been updated. - The
e100
driver has been updated. - The
enic
driver for Cisco 10G Ethernet devices has been updated to version 2.1.1.35, adding SR-IOV support. - The
igbvf
driver (Intel Gigabit Virtual Function Network driver) has been updated to version 2.0.1-k. - The
igb
driver for Intel Gigabit Ethernet Adapters has been updated to version 3.2.10-k, providing up-to-date hardware support, enhancements, and bug fixes. - The
bnx2
driver for the NetXtreme II 1 Gigabit Ethernet controllers has been updated to version 1.0.11. - The
tg3
driver for Broadcom Tigon3 Ethernet devices has been updated to version 3.120+. - The
qlcnic
driver for the HP NC-Series QLogic 10 Gigabit Server Adapters has been updated to version 5.0.26. - The
bna
driver has been updated. - The
r8169
driver has been updated to add support for the latest Realtek NICs (8168D/8168DP/8168E/8168EV) and increase reliability of older NICs. - The
qlge
driver has been updated to version 1.00.00.30. - The
cnic
driver has been updated to version 2.5.9, which improves error recovery on bnx2x devices, adds FCoE parity error recovery, increases the maximum amount of FCoE sessions, and adds other enhancements. - The
iwl6000
andiwlwifi
drivers have been updated to add support for the Intel Centrino Wireless-N 6235 series of Wi-Fi adapters. Theiwlwifi
also adds an option with 5GHz band can be disabled. - The wireless LAN subsystem has been updated. It introduces the
dma_unmap
state API and adds a new kernel header file:include/linux/pci-dma.h
. - The
atl1c
driver has been updated to the latest upstream version, which adds support for Atheros AR8151 v2 and Atheros AR8152 PCI-E Gigabit Ethernet Controllers.
- The
i915
driver has been updated. - Various graphics drivers have been updated with DRM support rebased to version 3.3-rc2.
- The
Wacom
driver has been updated, deprecating the wacompl package and obsoleting the wdaemon package. - The ALSA HDA audio driver has been updated to enable or improve support for new chipsets and HDA audio codecs.
- The btusb driver has been updated to include support for the Broadcom BCM20702A0 single-chip bluetooth processor.
- The
k10temp
driver from thehwmon
subsystem has been updated to add support for AMD family 12h/14h/15h of CPUs. - The ALPS Touchpad driver has been updated to add support for ALPS Touchpad protocol versions 3 and 4, and add support for touchpads with 4-directional buttons.
- The
jsm
driver has been updated to add Enhanced Error Handling (EEH). - The
mlx4_en
driver has been updated to version 2.0. - The
mlx4_core
driver has been updated to version 1.1.
Chapter 3. Networking
In Red Hat Enterprise Linux 6.3, the tc utility has been updated to work with the Quick Fair Scheduler (QFQ) kernel features. Users can now take advantage of the new QFQ traffic queuing discipline from userspace. This feature is considered a Technology Preview.
The rdma_bw and rdma_lat utilities (provided by the perftest package) are now deprecated and will be removed from the perftest package in a future update. Users should use the following utilities instead: ib_write_bw, ib_write_lat, ib_read_bw, and ib_read_lat.
With Red Hat Enterprise Linux 6.3, the System z qethconf tool provides information messages when a change of attributes did not work as expected.
Red Hat Enterprise Linux 6.3 adds IPv6 support to the qetharp tool for inspection and modification of the ARP cache of HiperSockets (real and virtual) operated in layer 3 mode. For real HiperSockets, the tool queries and shows the IPv6 address, and for guest LAN HiperSockets, it queries and shows IPv6 to MAC address mappings.
In Red Hat Enterprise Linux 6.3, NFSv4 introduces a module/kernel boot parameter, nfs.max_session_slots
, which sets the maximum number of session slots the NFS client will attempt to negotiate with the server. This limits the number of simultaneous RPC requests that the client can send to the NFSv4 server. Note that setting this value higher than max_tcp_slot_table_limit
has no effect.
Chapter 4. Resource Management
Red Hat Enterprise Linux 6.3 introduces the Network Priority (net_prio
) resource controller, which provides a way to dynamically set the priority of network traffic per each network interface for applications within various cgroups. For more information, refer to the Resource Management Guide.
The memory resource controller implements an Out-of-Memory (OOM) notifier which uses the new notification API. When enabled (by executing echo 1 > memory.oom_control
), an application is notified via eventfd when an OOM occurs. Note that OOM notification does not function for root cgroups.
The numad package provides a daemon for NUMA (Non-Uniform Memory Architecture) systems that monitors NUMA characteristics. As an alternative to manual static CPU pinning and memory assignment, numad provides dynamic adjustment to minimize memory latency on an ongoing basis. The package also provides an interface that can be used to query the numad
daemon for the best manual placement of an application. The numad package is introduced as a Technology Preview.
Chapter 5. Authentication and Interoperability
Previously, it was not possible to centrally manage host and user SSH public keys. Red Hat Enterprise Linux 6.3 includes SSH public key management for Identity Management servers as a Technology Preview. OpenSSH on Identity Management clients is automatically configured to use public keys which are stored on the Identity Management server. SSH host and user identities can now be managed centrally in Identity Management.
Red Hat Enterprise Linux 6.3 introduces the ability to control the SELinux context of a user on a remote system. SELinux user map rules can be defined and, optionally, associated with HBAC rules. These maps define the context a user receives depending on the host they are logging into and the group membership. When a user logs into a remote host which is configured to use SSSD with the Identity Management backend, the user's SELinux context is automatically set according to mapping rules defined for that user. For more information, refer to http://freeipa.org/page/SELinux_user_mapping. This feature is considered a Technology Preview.
SSH can now be set up to require multiple ways of authentication (whereas previously SSH allowed multiple ways of authentication of which only one was required for a successful login); for example, logging in to an SSH-enabled machine requires both a passphrase and a public key to be entered. The RequiredAuthentications1
and RequiredAuthentications2
options can be configured in the /etc/ssh/sshd_config
file to specify authentications that are required for a successful log in. For example:
~]# echo "RequiredAuthentications2 publickey,password" >> /etc/ssh/sshd_config
/etc/ssh/sshd_config
options, refer to the sshd_config
man page.
In Red Hat Enterprise Linux 6.3, SSSD includes a new Technology Preview feature: support for caching automount maps. This feature provides several advantages to environments that operate with autofs
:
- Cached automount maps make it easy for a client machine to perform mount operations even when the LDAP server is unreachable, but the NFS server remains reachable.
- When the
autofs
daemon is configured to look up automount maps via SSSD, only a single file has to be configured:/etc/sssd/sssd.conf
. Previously, the/etc/sysconfig/autofs
file had to be configured to fetch autofs data. - Caching the automount maps results in faster performance on the client and lower traffic on the LDAP server.
SSSD has changed the behavior of the debug_level
option in the /etc/sssd/sssd.conf
file. Previously, it was possible to set the debug_level
option in the [sssd]
configuration section and the result would be that this became the default setting for other configuration sections, unless they explicitly overrode it.
debug_level
option must always be specified independently in each section of the configuration file, instead of acquiring its default from the [sssd]
section.
~]# python /usr/lib/python2.6/site-packages/sssd_update_debug_levels.py
debug_level
option was specified in the [sssd]
section. If so, it adds that same level value to each other section in the sssd.conf
file for which debug_level
is unspecified. If the debug_level
option already exists explicitly in another section, it is left unchanged.
A new option, ldap_chpass_update_last_change
, has been added to SSSD configuration. If this option is enabled, SSSD attempts to change the shadowLastChange
LDAP attribute to the current time. Note that this is only related to a case when the LDAP password policy is used (usually taken care of by LDAP server), that is, the LDAP extended operation is used to change the password. Also note that the attribute has to be writable by the user who is changing the password.
Chapter 6. Subscription Management
Red Hat Enterprise Linux 6.3 includes a new tool to migrate RHN Classic customers to the certificate-based RHN. For more information, refer to the Red Hat Enterprise Linux 6 Subscription Management Guide.
Subscription Manager now disables gpgcheck for any repositories it manages which have an empty gpgkey
. To re-enable the repository, upload the GPG keys, and ensure that the correct URL is added to your custom content definition.
In Red Hat Enterprise Linux 6.3, during firstboot system registration, registering to Certificate-based Subscription Management is now the default option.
System profiles are now unregistered when they are deleted from the Customer Portal so that they no longer check in with certificate-based RHN.
Subscription manager now allows users to associate a machine with a preferred Service Level which impacts the auto subscription and healing logic. For more information on service levels, refer to the Red Hat Enterprise Linux 6 Subscription Management Guide.
Subscription manager now allows a user to select a specific release (for example, Red Hat Enterprise Linux 6.2), which will lock a machine to that release. Prior to this update, there was no way to limit package updates in the event newer packages became available as part of a later minor release (for example, Red Hat Enterprise Linux 6.3).
Chapter 7. Virtualization
7.1. KVM
KVM scalability enhancements in Red Hat Enterprise Linux 6.3 include:
- The maximum supported virtual guest size increased from 64 to 160 virtual CPUs (vCPUs).
- The maximum supported memory in a KVM guest increased from 512 GB to 2 TB.
KVM in Red Hat Enterprise Linux 6.3 includes support for:
- Intel Core i3, i5, i7 and other processors formerly code named “Sandy Bridge”,
- and new AMD family 15h processors (code named “Bulldozer”).
Steal time is the time that a virtual CPU waits for a real CPU while the hypervisor is servicing another virtual processor. KVM virtual machines can now calculate and report steal time, visible through tools like top and vmstat, which provides a guest with accurate CPU utilization data.
KVM in Red Hat Enterprise Linux 6.3 improved the access to qcow2
disk images (qcow2
is the default format) by making it more asynchronous, thus avoiding vCPU stalls and enhancing the overall performance during disk I/O.
The qemu-guest-agent package can be installed on virtual guest systems to provide the qemu-ga
service. The qemu-ga
service starts automatically (launching the /usr/bin/qemu-ga
daemon) if the /dev/virtio-ports/org.qemu.guest_agent.0
file exists. The daemon can be used to respond to a variety of requests for information and actions on the guests and it is currently encapsulated by libvirt on Red Hat Enterprise Linux 6 systems.
qemu-ga
daemon is used by libvirt to request that the guest VM suspend to disk or suspend to RAM. In addition to suspend operations, the daemon can respond to shutdown commands and file system freeze requests during a virtual machine live snapshot (to get a consistent disk state).
KVM can now virtualize Intel's performance monitoring unit (PMU) to allow virtual machines to use performance monitoring.
KVM in Red Hat Enterprise Linux 6.3 now supports dynamic virtual CPU allocation, also called vCPU hot plug, to dynamically manage capacity and react to unexpected load increases on their platforms during off-peak hours.
KVM Virtualization's storage stack has been improved with the addition of virtio-SCSI (a storage architecture for KVM based on SCSI) capabilities. Virtio-SCSI provides the ability to connect directly to SCSI LUNs and significantly improves scalability compared to virtio-blk. The advantage of virtio-SCSI is that it is capable of handling hundreds of devices compared to virtio-blk which can only handle 28 devices and exhausts PCI slots.
- attach a virtual hard drive or CD through the virtio-scsi controller,
- pass-through a physical SCSI device from the host to the guest via the QEMU scsi-block device,
- and allow the usage of hundreds of devices per guest; an improvement from the 28-device limit of virtio-blk.
KVM's power management features have been extended to include native support for S4 (suspend to disk) and S3 (suspend to RAM) states within the virtual machine, speeding up guest restoration from one of these low power states. In earlier implementations guests were saved or restored to or from a disk or memory that was external to the guest, which introduced latency.
/usr/share/seabios/bios-pm.bin
file for the VM bios instead of the default /usr/share/seabios/bios.bin
file.
Red Hat Enterprise Linux 6.3 introduces SR-IOV support for network interface controllers. This feature allows a NIC on a KVM host to be shared by KVM guests. For more information on SR-IOV, refer to Chapter 13. SR-IOV in the Virtualization Host Configuration and Guest Installation Guide. For information on SR-IOV on the be2net
driver, refer to Chapter 2, Device Drivers.
Red Hat Enterprise Linux 6.3 adds support for Time Stamp Counter (TSC) scaling to KVM for AMD Virtualization (AMD-V). This feature is capable of emulating a given TSC frequency on a KVM guest.
Support for the perf-kvm tool, which provides the ability to monitor guest performance from host, has been added. For more information, refer to the perf-kvm man page.
7.2. SPICE
Spice builds on KVM USB 2.0 host adapter emulation support, and enables remote USB redirection support that allows virtual machines running on servers to use remotely plugged USB devices on the client side.
7.3. libvirt
libvirt is now capable of controlling the state (up or down) of a link of the guest virtual network interfaces. This allows users to perform testing and simulation as though plugging and unplugging the network cable from the interface. This feature also lets users isolate guests in case any problems arise.
In Red Hat Enterprise Linux 6.3, libvirt has been updated to add support for the latest Intel Core i3, i5, i7 and other Intel processors, and family 15h microarchitecture AMD processors. With this update, libvirt now utilizes the new features these processors include.
Chapter 8. Clustering and High Availability
Luci, the web-based administrative UI for configuring clusters, has been updated to include the following:
- A confirmation dialog box appears when removing a clustered service.
- The UI includes an improved restart icon.
- Thebutton has been simplified.
- An option to enable debugging from the UI has been added.
As of Red Hat Enterprise Linux 6.3, luci authenticated sessions automatically time out after 15 minutes of inactivity. This period can be configured in the /etc/sysconfig/luci
file by modifying the who.auth_tkt_timeout
parameter.
The libqb package provides a library with the primary purpose of providing high performance client server reusable features, such as high performance logging, tracing, inter-process communication, and polling. This package is introduced as a dependency of the pacemaker package, and is considered a Technology Preview in Red Hat Enterprise Linux 6.3.
Because of the newly added libqb dependency, pacemaker now uses its logging functionality to provide less verbosity while keeping the ability to debug and support pacemaker.
Rgmanager includes a feature which enables it to utilize Corosync's Closed Process Group (CPG) API for inter-node locking. This feature is automatically enabled when Corosync's Redundant Ring Protocol (RRP) feature is enabled. Corosync's RRP feature is considered fully supported. However, when used with the rest of the High-Availability Add-Ons, it is considered a Technology Preview.
Chapter 9. Storage
A new implementation of LVM copy-on-write (cow) snapshots is available in Red Hat Enterprise Linux 6.3 as a Technology Preview. The main advantage of this implementation, compared to the previous implementation of snapshots, is that it allows many virtual devices to be stored on the same data volume. This implementation also provides support for arbitrary depth of recursive snapshots (snapshots of snapshots of snapshots …).
-s/--snapshot
option in the lvcreate
man page.
Logical Volumes (LVs) can now be thinly provisioned to manage a storage pool of free space to be allocated to an arbitrary number of devices when needed by applications. This allows creation of devices that can be bound to a thinly provisioned pool for late allocation when an application actually writes to the LV. The thinly-provisioned pool can be expanded dynamically if and when needed for cost-effective allocation of storage space. In Red Hat Enterprise Linux 6.3, this feature is introduced as a Technology Preview. You must have the device-mapper-persistent-data package installed to try out this feature. For more information, refer to the lvcreate
man page.
Most LVM commands require an accurate view of the LVM metadata stored on the disk devices on the system. With the current LVM design, if this information is not available, LVM must scan all the physical disk devices in the system. This requires a significant amount of I/O operations in systems that have a large number of disks.
lvmetad
daemon is to eliminate the need for this scanning by dynamically aggregating metadata information each time the status of a device changes. These events are signaled to lvmetad
by udev
rules. If lvmetad
is not running, LVM performs a scan as it normally would.
use_lvmetad
parameter in the /etc/lvm/lvm.conf
file, and enable the lvmetad
daemon by configuring the lvm2-lvmetad
init script.
Fiber Channel over Ethernet (FCoE) target mode is fully supported in Red Hat Enterprise Linux 6.3. This kernel feature is configurable via the targetcli utility, supplied by the fcoe-target-utils package. FCoE is designed to be used on a network supporting Data Center Bridging (DCB). Further details are available in the dcbtool(8)
and targetcli(8)
man pages (provided by the lldpad and fcoe-target-utils packages, respectively).
The expanded RAID support in LVM is now fully supported in Red Hat Enterprise Linux 6.3. LVM is now capable of creating RAID 4/5/6 logical volumes and supports mirroring of these logical volumes. The MD (software RAID) modules provide the backend support for these new features.
A new LVM configuration file parameter, activation/read_only_volume_list
, makes it possible to always activate particular volumes in read-only mode, regardless of the actual permissions on the volumes concerned. This parameter overrides the --permission rw
option stored in the metadata.
Chapter 10. General Updates
The Matahari agent framework (matahari-*) packages are deprecated starting with the Red Hat Enterprise Linux 6.3 release. Focus for remote systems management has shifted towards the use of the CIM infrastructure. This infrastructure relies on an already existing standard which provides a greater degree of interoperability for all users. It is strongly recommended that users discontinue the use of the matahari packages and other packages which depend on the Matahari infrastructure (specifically, libvirt-qmf and fence-virtd-libvirt-qpid). It is recommended that users uninstall Matahari from their systems to remove any possibility of security issues being exposed.
- The matahari packages are not installed by default starting with Red Hat Enterprise Linux 6.3 and are not enabled by default to start on boot when they are installed. Manual action is needed to both install and enable the
matahari
services. - The default configuration for qpid (the transport agent used by Matahari) does not enable access control lists (ACLs) or SSL. Without ACLs/SSL, the Matahari infrastructure is not secure. Configuring Matahari without ACLs/SSL is not recommended and may reduce your system's security.
- The matahari-services agent is specifically designed to allow remote manipulation of services (start, stop). Granting a user access to Matahari services is equivalent to providing a remote user with root access. Using Matahari agents should be treated as equivalent to providing remote root SSH access to a host.
- By default in Red Hat Enterprise Linux, the Matahari broker (
qpidd
running on port49000
) does not require authentication. However, the Matahari broker is not remotely accessible unless the firewall is disabled, or a rule is added to make it accessible. Given the capabilities exposed by Matahari agents, if Matahari is enabled, system administrators should be extremely cautious with the options that affect remote access to Matahari.
Red Hat Enterprise Linux 6.3 includes an scl-utils package which provides a runtime utility and packaging macros for packaging Software Collections. Software Collections allow users to concurrently install multiple versions of the same RPM packages on the system. Using the scl utility, users may enable specific versions of RPMs which are installed in the /opt
directory. For more information on Software Collections, refer to the Software Collections Guide.
With Red Hat Enterprise Linux 6.3, the openssl-ibmca package is part of the System z default installation. This avoids the need for manual installation steps.
Red Hat Enterprise Linux 6.3 provides the MySQL InnoDB storage engine as a plug-in for AMD64 and Intel 64 architectures. The plugin offers additional features and better performance than the built-in InnoDB storage engine.
Red Hat Enterprise Linux 6.3 includes full support for OpenJDK 7 as an alternative to OpenJDK 6. The java-1.7.0-openjdk packages provide the OpenJDK 7 Java Runtime Environment and the OpenJDK 7 Java Software Development Kit.
The java-1.7.0-oracle and java-1.7.0-ibm packages are now available in Red Hat Enterprise Linux 6.3.
The initscripts package has been updated to allow users to set the NIS domain name. This is done by configuring the NISDOMAIN
parameter in the /etc/sysconfig/network
file, or other relevant configuration files.
Previously, when certain groups were permitted to access all logs via ACLs, these ACLs were removed when the logs were rotated. In Red Hat Enterprise Linux 6.3, the logrotate utility supports ACLs, and logs that are rotated preserve any ACL settings.
The wacomcpl package has been deprecated and has been removed from the package set. The wacomcpl package provided graphical configuration of Wacom tablet settings. This functionality is now integrated into the GNOME Control Center.
The NumPy package which is designed to manipulate large multi-dimensional arrays of arbitrary records has been updated to version 1.4.1. This updated version includes these changes:
- When operating on
0-d
arrays,numpy.max
and other functions accept only the following parameters:axis=0
,axis=-1
, andaxis=None
. Using out-of-bounds axes indicates a bug, for which NumPy now raises an error. - Specifying the
axis > MAX_DIMS
parameter is no longer allowed; NumPy now raises an error, instead of behaving the same as whenaxis=None
was specified.
The rsyslog package has been upgraded to major version 5. This upgrade introduces various enhancements and fixes multiple bugs. The following are the most important changes:
- The
$HUPisRestart
directive has been removed and is no longer supported. Restart-type HUP processing is therefore no longer available. Now, when the SIGHUP signal is received, outputs (log files in most cases) are only re-opened to support log rotation. - The format of the spool files (for example, disk-assisted queues) has changed. In order to switch to the new format, drain the spool files, for example, by shutting down
rsyslogd
. Then, proceed with the Rsyslog upgrade, and startrsyslogd
again. Once upgraded, the new format is automatically used. - When the
rsyslogd
daemon was running in the debug mode (using the-d
option), it ran in the foreground. This has been fixed and the daemon is now forked and runs in the background, as is expected.
Appendix A. Component Versions
Component
|
Version
|
---|---|
Kernel
|
2.6.32-279
|
QLogic qla2xxx driver
|
8.04.00.02.06.3-k
|
QLogic qla2xxx firmware
|
ql23xx-firmware-3.03.27-3.1
ql2100-firmware-1.19.38-3.1
ql2200-firmware-2.02.08-3.1
ql2400-firmware-5.06.05-1
ql2500-firmware-5.06.05-1
|
Emulex lpfc driver
|
8.3.5.68.2p
|
iSCSI initiator utils
|
6.2.0.872-41
|
DM-Multipath
|
0.4.9-56
|
LVM
|
2.02.95-10
|
Appendix B. Revision History
Revision History | |||
---|---|---|---|
Revision 6-0.2 | Mon Feb 18 2013 | ||
| |||
Revision 1-0 | Wed Jun 20 2012 | ||
| |||
Revision 0-0 | Tue Apr 24 2012 | ||
|