About Clones and Cloning

To create a backup or read-only volume, the Volume Server begins by cloning the read/write source volume to create a clone. The Volume Server creates the clone automatically when you issue the vos backup or vos backupsys command (for a backup volume) or the vos release command (for a read-only volume). No special action is required on your part.

A clone is not a copy of the data in the read/write source volume, but rather a copy of the read/write volume's vnode index. The vnode index is a table of pointers between the files and directories in the volume and the physical disk blocks on the partition where the data resides. From the clone, backup and read-only volumes are created in the following manner:

Figure 1. File Sharing Between the Read/write Source and a Clone Volume

File Sharing Between the Read/write Source and a Clone Volume