About Oracle ASM Files

Files that are stored in Oracle ASM disk groups are called Oracle ASM files. Each Oracle ASM file is contained within a single Oracle ASM disk group. Oracle Database communicates with Oracle ASM in terms of files. This is similar to the way Oracle Database uses files on any file system. You can store the various file types in Oracle ASM disk groups, including:

  • Control files

  • Data files, temporary data files, and data file copies


  • Online redo logs, archive logs, and Flashback logs

  • RMAN backups

  • Disaster recovery configurations

  • Change tracking bitmaps

  • Data Pump dumpsets

Oracle ASM automatically generates Oracle ASM file names as part of file creation and tablespace creation. Oracle ASM file names begin with a plus sign (+) followed by a disk group name. You can specify user-friendly aliases for Oracle ASM files and create a hierarchical directory structure for the aliases.

The following sections describe the Oracle ASM file components: