HP Serviceguard Extended Distance Cluster for Linux A.01.
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Printing History Table 1 Printing History Printing Date Part Number Edition June 2007 T2808-90003 First Edition May 2008 T2403-90007 Second Edition The last printing date and part number indicate the current edition. Changes in the April 2008 edition includes information on support for multiple raid devices.
HP Serviceguard Extended Distance Cluster for Linux Release Notes 1 Chapter 1 HP Serviceguard Extended Distance Cluster for Linux Release Notes 5
HP Serviceguard Extended Distance Cluster for Linux Release Notes Announcements Announcements The HP Serviceguard Extended Distance Cluster (XDC) for Linux is a product that allows an HP Serviceguard for Linux cluster to operate across two separate sites providing disaster tolerance for applications. XDC uses the Linux Multiple Device (MD) driver’s software RAID capability and its associated tool, mdadm, to replicate data across those two sites.
HP Serviceguard Extended Distance Cluster for Linux Release Notes What’s In this Version What’s In this Version An extended distance cluster (also known as extended campus cluster) is a Serviceguard cluster that has alternate nodes located in different data centers separated by some distance. Using Linux MD, Serviceguard XDC ensures high availability of data.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Compatibility Information and Installation Requirements Compatibility Information and Installation Requirements To use Extended Distance Cluster, the following hardware and software must be installed and configured on all nodes.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Compatibility Information and Installation Requirements Software Requirements Following are the software requirements that you need for HP Serviceguard Extended Distance Cluster: • HP Serviceguard for Linux version A.11.16.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Compatibility Information and Installation Requirements Table 1-1 Supported Distance Between Sites (Continued) Type of Link Distance Long Wave Fiber 10 kilometers Dense Wave Division Multiplexing 100 kilometers Installing XDC Complete the following procedure to install HP Serviceguard Extended Distance Cluster: 1. Insert the product CD into the drive and mount the CD. 2. Open the terminal window. 3.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Compatibility Information and Installation Requirements # rpm -qa | grep xdc In the output, the product name, xdc -A.01.00-0 will be listed. The presence of this file verifies that the installation is successful. Support for a 4-Node Cluster XDC now supports a 4-node extended distance cluster for Linux. In this cluster configuration, 2 nodes are at one site, while the other 2 nodes form the other site.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Compatibility Information and Installation Requirements configuration, if a packages fails on a node in one site, it is targeted to startup on a node in a different site. Figure 1-1 and Table 1-2 elaborate this configuration order. Figure 1-1 4-node Datacenter Setup In this figure, nodes N1 and N2 are in Datacenter 1 at Site 1, while N3 and N4 are in Datacenter 2 in Site 2.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Compatibility Information and Installation Requirements Table 1-2 Failover Sequence (Continued) Node Site N3 Site 2 N2 Site 1 N4 Site 2 or N1 Site 1 N4 Site 2 N2 Site 1 N3 Site 2 In this table, every node is followed by a node from another site. If this order is not used, then site failures can result in data loss.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Compatibility Information and Installation Requirements What Manuals are Available for this Version For information about configuring Software RAID in your Extended Distance Cluster setup, see HP Serviceguard Extended Distance Cluster for Linux Deployment Guide available on the CD. Later versions of these documents will be available at http://www.docs.hp.com.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Compatibility Information and Installation Requirements Further Reading Additional information about related high availability topics may be found on Hewlett-Packard’s HA web page: http://www.hp.com/go/ha Support information, including current information on patches and known problems, is available from Hewlett-Packard IT center: http://itrc.hp.com (Americas and Asia Pacific) http://europe.itrc.hp.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Patches and Fixes in this Version Patches and Fixes in this Version There are no patches required for HP Serviceguard Extended Distance Cluster at the time of publication. However, this is subject to change without notice. For the most current information, contact your HP support representative or Hewlett Packard IT Resource Center. Fixes There are no known fixes at the time of this publication.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Known Problems and Workarounds Known Problems and Workarounds The following describes known problems with the XDC software. This is subject to change without notice. For the most current information, contact your HP support representative. More recent information on known problems and workarounds may also be available on the Hewlett Packard IT Resource Center: http://itrc.hp.com (Americas and Asia Pacific) http://europe.itrc.hp.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Known Problems and Workarounds Disks are resynchronized at all times • What is the problem? When data on two disks is not synchronized, Software RAID resynchronizes the entire disk, rather than only updating the changed data. This may happen even after a basic cluster failover. • What is the workaround? There is no workaround as this is expected behavior with an MD driver.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Known Problems and Workarounds # into an HBA driver), then references to MD, RAIDTAB, RAIDSTART, etc. # should be commented out. If the references are in the comments, they # can be ignored. References to MD devices, such as /dev/md0, should be # replaced with the appropriate multipath device name. # For example: # RAIDTAB="/usr/local/cmcluster/conf/raidtab.
HP Serviceguard Extended Distance Cluster for Linux Release Notes Software Availability in Native Languages Software Availability in Native Languages XDC software and documentation is not available in native language versions.
