1.2.21.2 Volume Attachments

To use a block volume, you must create a volume attachment.

An Exascale Direct Volume (EDV) attachment creates a association between the volume and an EDV device file on the Exadata compute node or Oracle Grid Infrastructure (GI) cluster hosting the attachment.

If you create a cluster-wide attachment, the EDV device file is created on every node in the GI cluster. If you create a node-specific attachment, the corresponding EDV device is only created on that node.

After attachment, the volume can be used as a raw block storage device or to support a file system. To implement Oracle Advanced Cluster File System (ACFS) on Exascale block volume storage, you must use an EDV attachment.

The I/O for each attachment is serviced by an EDV server process. Automatic data encryption and decryption occurs within the EDV process.

In addition to general file storage, an EDV attachment may be used to support Oracle Database data files for versions before Oracle Database 23ai. However, an EDV attachment cannot be used for a bootable volume.

Exascale supports the simultaneous use of multiple attachments for each volume, which can be used to support various types of clustered file systems.