Sun StorageTek SL8500 is powerful tape library which enables 24×7 availability with fully redundant and replaceable robotics. StorageTek SL8500 modular library system is Sun extreme machine in storage. No matter how big you are or fast you grow, it totally accommodates your offline tape needs for data backup, archiving, and protection. It’s modular and can expand to 448 tape drives and 70,0001 tape slots–just under 200 feet long. just go to here for detail features and specifications.
Sun StorageTek SL8500 is an enterprise-class robotic tape library. One library stores a maximum of 6.5 petabytes of storage spread over 10000 cartridges. It supports a maximum of 64 tape drives. It uses up to 8 indepentent robots in each library. Up to seven such libraries can be connected side-by-side and automatically pass tapes between each other, forming a complex capable of storing over 70 PB of data and mounting 448 tape drives. Each tape drive installed in the sl8500 library has an independent data path. The aggregate data rate for all drives is 193.2 TB/hr. (Wikipedia).
for more detail, watch the video below:
Discovering SL8500:
Sun StorageTek SL8500 Product Tour (1 of 2):
Sun StorageTek SL8500 Product Tour (2 of 2)
SAIFUL AZIZ's BLOG 
Hi Aziz,
I have moved to mainframe Storage recently and working on SL8500 tape library. However, this library seems to be quite hard to understand as it deals with MVC’s, VTV’s VTS, ACS and so on. can you please let me know this environment in layman terms for my better understanding?
hello Prasad, you need to learn more about VTCS/MVS, go to below Oracle’s documentation:
http://docs.oracle.com/cd/E19306-01/index.html
http://docs.oracle.com/cd/E19742-01/index.html