Linux Clustering
Both Red Hat and Oracle have developed clustering software for Linux.
OCFS2, the Oracle Cluster File System was added to the official Linux kernel with version 2.6.16, in January 2006. The alpha-quality code warning on OCFS2 was removed in 2.6.19.
Red Hat's cluster software, including their DLM and GFS2 was officially added to the Linux kernel with version 2.6.19, in November 2006.
Both systems use a DLM modeled on the venerable VMS DLM. Oracle's DLM has a simpler API. (the core function, dlmlock, has eight parameters, whereas the VMS service and Red Hat's dlm_lock both have 11.)
Read more about this topic: Distributed Lock Manager