IBM L5X, Инструкция по установке и эксплуатации

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If the switch is in the locked position, (solid red), data cannot be written to
the tape. If the switch is in the unlocked position (black void), data can be written
to the tape.
If you must manually set the write-protect switch, slide it left or right to the
desired position.
WORM (Write Once, Read Many) cartridge
Certain records-retention and data-security applications require a Write Once, Read
Many (WORM) method for storing data on tape. The LTO Ultrium generation 3, 4
and 5 drives enable WORM support when a WORM tape cartridge is loaded into
the drive.
Because standard read/write media are incompatible with the WORM feature, a
specially formatted WORM tape cartridge (see Figure 10) is required. Each WORM
cartridge has a unique, worldwide cartridge identifier (WWCID), which is
comprised of the unique CM chip serial number and the unique tape media serial
number.
Type of cartridge Case color Native data capacity Recording format
1
Ultrium 5 WORM Burgundy and silvery
gray
1,500 GB (3,000 GB at 2:1
compression) Reads and writes data on 1,280 tracks,
16 tracks at a time
Ultrium 4 WORM Green and silvery gray 800 GB (1,600 GB at 2:1
compression)
Reads and writes data on 896 tracks, 16
tracks at a time
Ultrium 3 WORM Slate blue and silvery
gray
400 GB (800 GB at 2:1
compression) Reads and writes data on 704 tracks, 16
tracks at a time
1
The first set of tracks, which is 16 for Ultrium 5, 4 and 3 cartridges, 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 of your data is written.
Data security on WORM media
Certain built-in security measures help make sure that the data written on a
WORM cartridge does not become compromised, for example:
v The format of a WORM cartridge is unlike that of standard read/write media.
This unique format prevents a drive that lacks WORM-capable firmware from
writing on a WORM cartridge.
v
When the drive senses a WORM cartridge, the firmware prohibits the changing
of user data already written on the tape. The firmware keeps track of the last
appendable point on the tape.
Figure 10. Ultrium data cartridge on the left; WORM cartridge on the right
Chapter 4. Using Ultrium media
43