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fail with an I/O error. In some cases, depending on the client implementation, the failure may be more
severe, including the possibility of a system crash.
It is important that you take precautions to ensure that NFS referral exports are not accessed by
clients that do not support them.
GFS2 is an incremental advancement of GFS. This update applies several significant improvements
that require a change to the on-disk file system format. GFS file systems can be converted to GFS2
using the utility gfs2_convert, which updates the metadata of a GFS file system accordingly.
While much improved since its introduction in Red Hat Enterprise Linux 5, GFS2 remains a
Technology Preview. The release notes included in the distribution incorrectly states that GFS2 is
fully supported. Nevertheless, benchmark tests indicate faster performance on the following:
heavy usage in a single directory and faster directory scans (Postmark benchmark)
synchronous I/O operations (fstest benchmark test indicates improved performance for
messaging applications like TIBCO)
cached reads, as there is no longer any locking overhead
direct I/O to preallocated files
NFS file handle lookups
df, as allocation information is now cached
In addition, GFS2 also features the following changes:
journals are now plain (though hidden) files instead of metadata. Journals can now be
dynamically added as additional servers mount a file system.
quotas are now enabled and disabled by the mount option quota=
quiesce is no longer needed on a cluster to replay journals for failure recovery
nanosecond timestamps are now supported
similar to ext3, GFS2 now supports the data=ordered mode
attribute settings lsattr() and chattr() are now supported via standard ioctl()
file system sizes above 16TB are now supported
GFS2 is a standard file system, and can be used in non-clustered configurations
Installing Red Hat Enterprise Linux 5.1 on HP BL860c blade systems may hang during the IP
information request stage. This issue manifests when you have to select OK twice on the Configure
TCP/IP screen.
If this occurs, reboot and perform the installation with Ethernet autonegotiation disabled. To do this,
use the parameter ethtool="autoneg=off" when booting from the installation media. Doing so
does not affect the final installed system.
The nohide export option is required on referral exports (i.e. exports that specify a referral server).
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Red Hat Enterprise Linux 5 5.1 Release Notes
This is because referral exports need to "cross over" a bound mount point. The nohide export
option is required for such a "cross over" to be successful.
For more information on bound mounts, refer to m an exports 5.
This update includes the lvm 2 event monitoring daemon. If you are already using lvm 2 mirroring,
perform the following steps to ensure that all monitoring functions are upgraded properly:
1. Deactivate all mirrored lvm 2 logical volumes before updating. To do this, use the command
lvchange -a n .
2. Stop the old lvm2 event daemon using killall -HUP dm eventd.
3. Perform the upgrade of all related RPM packages, namely device-m apper and lvm 2.
4. Reactivate all mirrored volumes again using lvchange -a y
volume>.
Rapid Virtualization Indexing (RVI) is now supported on 64-bit, 32-bit, and 32-bit PAE kernels.
However, RVI can only translate 32-bit guest virtual addresses on the 32-bit PAE hypervisor.
As such, if a guest is running a PAE kernel with more than 3840MB of RAM, a wrong address
translation error will occur. This can crash the guest.
It is recommended that you use the 64-bit kernel if you intend to run guests with more than 4GB of
physical RAM under RVI.
Running 16 cores or more using AMD Rev F processors may result in system resets when
performing fully-virtualized guest installations.
If your system uses a P600 SmartArray controller, a machine check error may occur while running the
virtualized kernel. When this occurs, dom 0 will reboot.
To prevent this, run the following shell script at the beginning of each boot:
#!/bin/bash
for x in $(lspci -d 103c:3220 | awk '{print $1}'); do
val=$(setpci -s $x 40.b)
val=$(( 0x$val | 1 ))
setpci -s $x 40.b=$(printf '%x' $val)
done
If you encounter a guest installation failure, it is recommended that you restart the xend daemon
before attempting to install a new guest.
Installing the system tap-runtim e package will result in a transaction check error if the
systemtap package is already installed. Further, upgrading Red Hat Enterprise Linux 5 to 5.1 will
also fail if the systemtap package is already installed.
As such, remove the system tap package using the command rpm -e system tap-0.5.12-
1.e15 before installing systemtap-runtime or performing an upgrade.
Kernel modules such as e1000 and qla2xxx cannot be unloaded if you are running the virtualized
kernel.
As such, if you install any third-party drivers, it is recommended that you reboot the system. [ Pobierz całość w formacie PDF ]