Slots and Tiers
Cartridge storage slots in the tape library hold one or more tape cartridges. The TS4500 and Diamondback library offers high-density (HD) slots that are designed to greatly increase storage capacity without increasing frame size or required floor space. Each cartridge within a high-density slot stored is said to occupy a tier within in the slot.
HD storage slots in TS4500 have up to five tiers of storage and can hold up to five LTO cartridges with one in each tier. For 3592 media type cartridges, the number of tiers is four. These HD slots are installed in the main part of the library frame while the normal storage slots that hold only one tier are stored in the door of the library. The tape library ensures that the most recently used cartridges are kept in higher tiers closer to the front of the slot for faster access.
HD storage slots in Diamondback have up to nine tiers of storage and can hold up to five LTO cartridges.
Storage slots are a shared resource in the library and not directly assigned to specific logical libraries. The Advanced Library Management System (ALMS) allows logical libraries to be added or deleted without disrupting operation. All storage slots are pooled (available on a first-come, first-served basis) to each logical library based on cartridge insert operations.