What are Diskgroup’s and Failuregroups?
Diskgroup is a terminology used for logical structure which holds the database files. Each Diskgroup consists of Disks/Raw devices where the files are actually stored. Any ASM file is completely contained within a single disk group. However, a disk group might contain files belonging to several databases and a single database can use files from multiple disk groups. Failuregroups are used when using Normal/High Redundancy. They contain the mirrored ASM extents and must be containing different disks and preferably on separate disk controller.
