The first version of OCFS was developed with the main focus to accommodate Oracle database files for clustered databases. Because of that it was not a POSIX compliant file system. With version 2 the POSIX features were included.
OCFS2 (version 2) was integrated into the version 2.6.16 of Linux kernel. Initially, it was marked as "experimental" (Alpha-test) code. This restriction was removed in Linux version 2.6.19. With kernel version 2.6.29 more features have been included into ocfs2, most notably access control lists and quota.