To ensure system availability by eliminating single points of failure, SIMS, SunDS binaries, configuration files, and data must be mirrored on replicated disks. Sun Cluster 2.1 includes the Sun Enterprise Volume Manager, on which SIMS/HA depends to provide redundant storage.To enable SIMS back up quickly after a fail-over, it's important that the file systems holding the SIMS writable data recover quickly and be restored to a consistent state.
Because the base Solaris UNIX File System (UFS) does not synchronously write file meta-data at fsync() time, fsck times can be large and the file system state may not be completely recovered. For example, small files that were created right before a crash might not exist after fsck and remount. SIMS/HA depends on the Veritas File System (VxFS) 3.2.4 to provide a file system with these characteristics.
Note - Since Sun Cluster 2.1 does not include Veritas File System (VxFS) 3.2.4, it must be purchased.