Copyright © 2007 Red Hat, Inc. and others. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0, available at http://www.opencontent.org/openpub/.
The following topics are covered in this document:
Some updates on Red Hat Cluster Suite 4 Update 5 may not appear in this version of the Release Notes. Please consult the following URL for an updated version of the Release Notes:
Synchronous Mirroring has been added to the Cluster Logical Volume Manager (CLVM). This allows two leg mirrors to use a single transaction log, which track blocks as they are duplicated. The write will not complete until both legs have been updated.
If one leg of the mirror is lost, the operation will continue on the remaining leg. Note that even a temporary loss of one leg will necessitate a full recovery. This recovery will occur in the background.
More than two legs can be configured. However, the loss of any leg will require dropping down to one leg and recreating all others.
Red Hat Cluster Suite 4 Update 5 includes Conga, a new web-based management interface for installing, configuring and managing one or more clusters. It provides:
a secure way to remotely install rpms and configure a cluster from a single web interface
cluster fencing setup
failover configuration for applications across the cluster
provisions storage, including physical and logical volumes as well as local and cluster file systems
CIM and SNMP MIB reporting is now supported. Information reported includes:
cluster name and general status
cluster nodes and their status
a list of managed services, including status and location
GFS for Red Hat Enterprise Linux 4 Update 5 now includes the df command, which significantly improves the execution time of the statfs call. This option uses cached information for the calculation of used space. For the majority of users this is sufficiently accurate.
To use the Fast statfs option, start by issuing the following command on each node:
gfs_tool settune <mount point> statfs_fast 1
This command must be run after mount. Note that Fast statfs is not persistent after an unmount. It is recommended that you use a wrapper script to perform the mount then set the flag. Setting the flag can be integrated into the gfs init script in /etc/init.d/gfs.
Fast statfs can also be turned off for mounted volumes. To do this, issue the following command on all nodes:
gfs_tool settune <mount point> statfs_fast 0
Red Hat Cluster Suite 4 Update 5 now features the following support enhancements:
The fence_drac agent now supports DRAC 4/I, and its telnet timeout has been increased. In addition, DRAC 4/P is now supported, and has been tested for 4/p firmware version 1.40.
Baytech RPC-5NC Remote Power Control Switch is now supported.
SCSI reservations are now supported. Note that the SCSI reservation feature does not work with dm-multipath.
DRAC5 is now supported.
PowerPC is now supported.
The following errata contain complete listings of issues resolved in Red Hat Cluster Suite 4 Update 5: