IBM System Storage TS2240, Руководство по установке, эксплуатации и обслуживанию

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Data Cartridge
All generations of IBM Ultrium data cartridges contain 1/2-inch, dual-coat,
metal-particle tape. When processing tape in the cartridges, Ultrium Tape Drives
use a linear, serpentine recording format.
Each generation of data cartridge is identified by case color, native data capacity,
recording format and nominal cartridge life.
Data Cartridge Case Color
Native Data
Capacity
Recording Format*
Nominal Cartridge Life
(load/unload cycles)
Ultrium 4 Green 800 GB (1600 GB
at 2:1 compression)
Reads and writes data on 896
tracks, sixteen tracks at a time.
20,000
Ultrium 3 Slate Blue 400 GB (800 GB at
2:1 compression)
Reads and writes data on 704
tracks, sixteen tracks at a time
20,000
Ultrium 2 Purple 200 GB (400 GB at
2:1 compression)
Reads and writes data on 512
tracks, eight tracks at a time
10,000
Ultrium 1 Black 100 GB (200 GB at
2:1 compression)
Reads and writes data on 384
tracks, eight tracks at a time
5,000
* The first set of tracks (sixteen for Ultrium 4 and 3; eight for Ultrium 2 and 1) is written from near the beginning of
the tape to near the end of the tape. The head then repositions to the next set of tracks for the return pass. This
process continues until all tracks are written and the cartridge is full, or until all data is written.
Cartridge Memory Chip (LTO-CM)
All generations of the IBM LTO Ultrium Data Cartridges include a Linear Tape-Open
Cartridge Memory (LTO-CM) chip (
1
in Figure 4-1 on page 4-1), that contains
information about the cartridge and the tape (such as the name of the manufacturer
that created the tape), as well as statistical information about the cartridge’s use.
The LTO-CM enhances the efficiency of the cartridge. For example, the LTO-CM
stores the end-of-data location which, when the next time this cartridge is inserted
and the WRITE command is issued, enables the drive to quickly locate the
recording area and begin recording. The LTO-CM also aids in determining the
reliability of the cartridge by storing data about its age, how many times it has been
loaded, and how many errors it has accumulated. Whenever a tape cartridge is
unloaded, the tape drive writes any pertinent information to the cartridge memory.
The storage capacity of the LTO Generation 4 LTO-CM is 8160 bytes. LTO
Generations 1, 2, and 3 have an LTO-CM capacity of 4096 bytes.
Write-Protect Switch
The position of the write-protect switch on the tape cartridge (see
4
in Figure 4-1
on page 4-1) determines whether you can write to the tape. If the switch is set to:
v
The locked position (solid red), data cannot be written to the tape.
v The unlocked position (black void), data can be written to the tape.
If possible, use your server’s application software to write-protect your cartridges
(rather than manually setting the write-protect switch). This allows the server’s
software to identify a cartridge that no longer contains current data and is eligible to
become a scratch (blank) data cartridge. Do not write-protect scratch (blank)
cartridges; the tape drive will not be able to write new data to them.
4-2
TS2240 Tape Drive Setup, Operator and Service Manual