Before these new frames, customers had two choices for their tape cartridges: keep them in an automatedtape library, or on an external shelf. Most of the critics of tape focus almost entirely on the problemsrelated to the latter. When tapes are placed outside of automation, you need human intervention to findand fetch the tapes, tapes can be misplaced or misfiled, tapes can be dropped, tapes can get liquids spilledon them, and so on. These problems just don't happen when stored in automated tape libraries.
Until now, the number of cartridges were limited to the surface area of the wall accessible by the roboticpicker. Whether the robot rotates in a circle picking from dodecagon walls, or back and forth from longrectangular walls, the problem was the same.
|But what about tapes that may not need to be readily accessible, but still automated? With the newhigh density frames, you can now stack tapes several cartridges deep, spring loaded deep shelves thatpush the tape cartridges up to the front one at a time. The high-density frame design might have been inspired by thefamous [Pez] candy dispenser, but at 70.9 inches, does not beat the[World's Tallest Pez Dispenser].|
(Note: PEZ® is a registered trademark of Pez Candy, Inc.)
In a regular cartridge-only frame, like the D23, you have slots for 200 cartridges on the left, and 200 cartridges on the right, and the robotic picker can pull out and push back cartridges into any of theseslot positions. In the new S24, there are still 200 slots on the left, now referred to as "tier 0",but up to 800 cartridges on the right. In each slot there are up to four 3592 cartridges, the positionimmediately reachable to the picker is referred to as "tier 1", and the ones tucked behindare "tier 2", "tier 3" and "tier 4".
|Tier 0||<- - - S24 frame - - - >||Tier 1||Tier 2||Tier 3||Tier 4|
|Tape A||Robotic Picker||Tape B||Tape C||Tape D||Tape E|
We have fun slow-motion videos we show customers on how these work. For example, in the diagram above, let'ssuppose you want to fetch Tape E in the "tier 4" position. The following sequence happens:
- Robotic picker pulls "tier 1" tape cartridge B, and pushes it into another shelf slot. Tapes C, D and E get pushed up to be Tiers 1, 2 and 3 now.
- Robotic picker pulls "tier 1" tape cartridge C, and puts it in another shelf slot. Tapes D and E get pushed up to be Tiers 1 and 2 now.
- Robotic picker pulls "tier 1" tape cartridge D, and puts it in another shelf slot. Tape E gets pushed up to be Tier 1 now.
- Robotic picker pulls "tier 1" tape cartridge E, this is the tape we wanted, and can move it to the drive.
- The other three cartridges (B, C and D) are then pulled out of the temporary slot, and pushed back into their original order.
In this manner, the most recently referenced tape cartridges will be immediately accessible, and the ones leastreferenced will eventually migrate to the deeper tiers. The 3592 cartridges can be used with either TS1120 orTS1130 drives. Each cartridge can hold up to 3TB of data (1TB raw, at 3:1 compression), so the entire framecould hold 3PB in just 10 square feet of floor space. Five D23 frames could be consolidated down to two S24 frames.The S24 frame comes in "Capacity on Demand" pricing options. The base model of the S24 has just tiers 0, 1 and 2, for a total capacity of 600 cartridges. You can then later license tiers 3 and 4 when needed.
The S54 is basically similar in operation, but for LTO cartridges. It works with any mix of LTO-1, LTO-2, LTO-3 andLTO-4 cartridges.The left side holds tier 0 as before, but the right side has up to five LTO cartridges deep. For Capacity on Demand pricing,the base model supports 660 cartridges (tiers 0,1,2), with options to upgrade for the additional 660 cartridges.The total 1320 cartridges could hold up to 2.1 PB of data (at 2:1 compression). One S54 frame could replacethree traditional S53 frames that held only 440 LTO cartridges each.
If you have both TS1100 series and LTO drives in your TS3500 tape library, then you can haveboth S24 and S54 frames side by side.
To learn more, here is the official[IBMAnnouncement Letter].