Quantum DLTtape SDLT 220, Руководство пользователя

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SDLT 220 and SDLT 320 Product Manual CHAPTER 3: Drive Specifications
81-85002-01 March 2004 3-5
To provide access to backup tapes written on DLTtape tape drives, the SDLT drive
will read, but not write, DLTtape IV cartridges; this is known as backward-read
compatibility (BRC) mode. The drive uses a different head while operating in
BRC mode; the BRC head life is guaranteed to be a minimum of 10,000 tape
motion hours.
N
OTE
: Quantum Corporation does not warrant that predicted
MTBF is representative of any particular unit installed for
customer use. Actual figures vary from unit to unit.
3.1.8 Media Durability
Media durability is 1,000,000 passes; a media pass is defined as movement of the
tape head over the surface of the media (in either direction). Alternatively stated,
each DLTtape IV and Super DLTtape I media provides 250 full tape uses; a full
tape use (end-to-end) is considered to be the type of operation that occurs when a
customer writes very large filesets to the tape.
3.1.9 Cartridge Life Expectancy
Table 3-5 shows the number of load and unload cycles you can expect before the
tape cartridges need to be replaced.
Table 3-5.
Loading and Unloading the Media Cartridge (Maximum)
DLTtape IV
Tape Cartridge Super DLTtape I
Tape Cartridge
Cartridge load/unload cycles† 10,000 100,000
Tape insertions
‡
5,000 5,000
† Load and unload cycles are rated at 5,000 for the cartridge itself.
‡ An insertion is when a tape is inserted into the receiver, loaded to BOT,
calibrated, and then unloaded.