Monitoring drive usage by logical library
The drive usage bar indicates the current drive usage for the logical library. The number on the right of the bar is the total number of drives assigned to the logical library. The bar fills as a percentage of the number of drives that are in use.
The bar turns red if all of the drives in the logical library are being used. If all of the drives are being used frequently, the logical library could be over-allocated and you should consider adding more drives to the logical library.