Volume Set Specification
Volume Sets (the spanning of multiple disk surfaces into one functional volume) is one of the significant new features of the InveStore v4 Storage Management Software. This allows the user to go beyond the limitations of individual disk cartridges, thereby increasing the capacity and versatility of how applications use the storage server.
Creating a Volume Set uses a process of combining individual media cartridges within a library device, and making them appear to be a single contiguous volume.
The first surface of the first disk cartridge is typically referred to as the root volume, and all other surfaces are referred to as member volumes. The InveStore v4 data allocation algorithm allocates space from the first member volume until it is completely full, then continues writing to other members to that set.
To prevent catastrophic data loss, the InveStore algorithm does not store the entire directory on the root volume. Each surface within the volume set is self-describing.
Should any surface within that Volume Set become damaged, only the data on that surface is lost.
All other members of the volume set are fully accessible allowing any volume set to be partially mounted and any number of cartridges can be offline for the volume set and the remaining surfaces will be fully accessible.