Most documentation on the net is about how to run a cluster-in-a-box under Vmware. Very few seem to care about protecting Vmware guests under real RedHat cluster with a shared storage. This article is just about it. While I would not recommend using Vmware in such a setup, it has been the case, and that…
There is a major confusion among DBAs regarding how to setup raw devices for Oracle RAC or Oracle Clusterware. This confusion is caused by the turn RedHat took in how to define raw devices. Raw devices are actually a manifestation of character devices pointing to block devices. Character devices are non-buffered, so they act as…
I have had a system panicking when running the mentioned below configuration: RedHat RHEL 4 Update 6 (4.6) 64bit (x86_64) Dell PowerEdge servers Oracle RAC 11g with Clusterware 11g EMC iSCSI storage EMC PowerPate Vote and Registry LUNs are accessible as raw devices Data files are accessible through ASM with libASM During reboots or shutdowns,…
Setting up an Oracle ASM disks is rather simple, and the procedure can be easily obtained from here, for example. This is nice and pretty, and works well for most environments. EMC PowerPath creates meta devices which utilize the underlying paths, as mod_scsi sees them in Linux, without hiding them (unlike IBM’s RDAC, for example)….
I have been struggling with RH Cluster 4 with VMware fencing device. This was also a good experiance with qdiskd, the Disk Quorum directive and utilization. I have several conclusions out of this experience. First, the configuration, as is: <?xml version=”1.0″?> <cluster alias=”alpha_cluster” config_version=”17″ name=”alpha_cluster”> <quorumd interval=”1″ label=”Qdisk1″ min_score=”3″ tko=”10″ votes=”3″> <heuristic interval=”2″ program=”ping vm-server…
Cluster fencing – Unlike many common thoughts, high-availability is not the highest priority of an high-availability cluster, but only the 2nd one. The highest priority of an high-availability cluster is maintenance of data integrity by prevention of multiple concurrent access of nodes to the shared disk. On different cluster, depending on the vendor, this can…
