Worm (Write Once, Read Many) Cartridge; Ultrium Data Cartridge On The Left; Worm - IBM LTO Ultrium 4 Installation And User Manual

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
and 4 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 8) is required. Each WORM
cartridge has a unique, worldwide cartridge identifier (WWCID), which comprises
the unique CM chip serial number and the unique tape media serial number.
Figure 8. Ultrium Data Cartridge on the left; WORM Cartridge on the right
Type of cartridge
Ultrium 4 WORM Green and Silvery gray 800 GB (1600 GB at 2:1
Ultrium 3 WORM Slate Blue and Silvery
* 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.
Data security on WORM media
Certain built-in security measures help ensure that the data written on a WORM
cartridge does not become compromised, for example:
v The format of a WORM tape cartridge is unlike that of standard read/write
v When the drive senses a WORM cartridge, the firmware prohibits the changing
WORM media errors
The following conditions cause WORM media errors to occur:
v Information in the servo manufacturer word (SMW) on the tape must match
Case color Native data capacity
compression)
400 GB (800 GB at 2:1
gray compression)
media. This unique format prevents a drive that lacks WORM-capable firmware
from writing on a WORM tape cartridge.
or altering of user data already written on the tape. The firmware keeps track of
the last appendable point on the tape.
information from the cartridge memory (CM) module in the cartridge. If it does
not match:
– a full-high tape drive will post a media Error Code 7 on the single-character
display (SCD)
Recording format*
Reads and writes data on 896 tracks,
sixteen tracks at a time.
Reads and writes data on 704 tracks,
sixteen tracks at a time
Chapter 4. Using Ultrium media
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