Table 2-27 lists the data rates for the LTO-6 tape drives.  The LTO-6 tape drives are encryption capable, which means that they can convert data into a  cipher that ensures data security. System-managed encryption and library-managed  encryption and associated IBM Security Key Lifecycle Manager (SKLM) access are all  available as a chargeable licensed key (FC 1604, Transparent LTO Encryption). A key is  required to encrypt and decrypt the data. How a key is generated, maintained, controlled, and  transmitted depends on the operating environment where the tape drive is installed.  Certain data management applications can manage keys. For an alternative solution, IBM  provides a key manager that works with the keystore of your choice to perform all necessary  key management tasks. No recovery exists for lost encryption keys.  The  Surface Control Guiding Mechanism  is designed to guide the tape along the tape path in  the LTO-6 tape drive. This method uses the surface of the tape rather than the edges to  control tape motion.  LTO-6 tape drives use flangeless rollers so that the media can float naturally. The Surface  Control Guiding Mechanism helps to reduce tape damage (especially to the edges of the  tape) and tape debris that comes from the damaged edges and can accumulate in the head  area.  The LTO-6 tape drives communicate with the TS4500 tape library through an internal  Ethernet interface and use Statistical Analysis and Reporting System (SARS) to isolate  failures between media and hardware. SARS uses the data cartridge performance history  that is saved in the cartridge memory module and the drive performance history that is kept in  the drive flash Electronically Erasable Programmable Read-Only Memory (EEPROM) to help  determine the likely cause of the failure. SARS can cause the drive to request a cleaning tape  to mark the media as degraded and to indicate that the hardware is degraded.  Media partitioning is now available with the LTO-6 tape drive. Media partitioning allows for  faster data access by splitting the cartridge into two media partitions. WORM media is not  partitionable. 160  IBM TS4500 R6 Tape Library Guide Media partitioning Statistical Analysis and Reporting System (SARS) Surface Control Guiding Mechanism Table 2-27 LTO-6 tape drive speed matching data rates Performance  parameters LTO-6 tape cartridge LTO-5 tape cartridge LTO-4 tape cartridge  read only Speed matching  data rates in MBps 160.00 150.77 141.54 132.31 123.08 113.85 104.62 095.38 086.15 076.92 067.69 058.46 049.23 040.00 140.0 130.0 120.0 112.7 105.5 098.2 090.9 083.6 076.4 069.1 061.8 053.5 046.3 040.0 120.0 113.1 106.1 099.2 092.3 085.3 078.6 071.4 064.6 057.6 050.8 043.8 036.9 030.5