Oracle ASM Storage Limits

参考：Automatic Storage Management Administrator's Guide 19（Part II Oracle ASM Instances and Disk Groups）

Oracle ASM has the following limits on the number of disk groups, disks, and files:

• 511 disk groups in a storage system for Oracle Database 12c Release 1 or later

• 10,000 Oracle ASM disks in a disk group

• 65,530 Oracle ASM disks in a storage system

• 1 million files for each disk group

Without any Oracle Exadata Storage, Oracle ASM has the following storage limits if the COMPATIBLE.ASM or COMPATIBLE.RDBMS disk group attribute is set to less than 12.1:

• 2 terabytes (TB) maximum storage for each Oracle ASM disk

• 20 petabytes (PB) maximum for the storage system

Without any Oracle Exadata Storage, Oracle ASM has the following storage limits if the COMPATIBLE.ASM and COMPATIBLE.RDBMS disk group attributes are set to 12.1 or greater:

• 4 PB maximum storage for each Oracle ASM disk with the allocation unit (AU) size equal to 1 MB

• 8 PB maximum storage for each Oracle ASM disk with the AU size equal to 2 MB

• 16 PB maximum storage for each Oracle ASM disk with the AU size equal to 4 MB

• 32 PB maximum storage for each Oracle ASM disk with the AU size equal to 8 MB

• 320 exabytes (EB) maximum for the storage system

With all Oracle Exadata Storage, Oracle ASM has the following storage limits:

• 4 PB maximum storage for each Oracle ASM disk with the AU size equal to 1 MB

• 8 PB maximum storage for each Oracle ASM disk with the AU size equal to 2 MB

• 16 PB maximum storage for each Oracle ASM disk with the AU size equal to 4 MB

• 32 PB maximum storage for each Oracle ASM disk with the AU size equal to 8 MB

• 320 EB maximum for the storage system

The maximum size limit of a disk group equals the maximum disk size multiplied by the maximum number of disks in a disk group (10,000).

The maximum number of disks across all disk groups is 65,530 disks. However, the total number of disks that can be in one disk group is limited to 10,000 disks. This is a limitation on the number of Oracle ASM disks, not necessarily the number of physical storage devices. A storage array could group multiple physical storage devices into a LUN that is used as a single Oracle ASM disk.

File size limits are dependent on the value of the disk group compatibility attributes. Oracle ASM supports file sizes greater than 128 TB in any redundancy mode when the COMPATIBLE.RDBMS disk group attribute is set greater than 10.1.

If COMPATIBLE.RDBMS is set to 10.1, the file size limits are less. For example, with COMPATIBLE.RDBMS equal to 10.1 and the AU size equal to 1 MB, Oracle ASM file size limits are:

• External redundancy: 16 TB

• Normal redundancy: 5.8 TB

• High redundancy: 3.9 TB