Example
In an extreme case, suppose that the host is sending a series of
one-byte logical blocks to the CTS. Tape capacity is used as follows:
1. The CTS places the first two one-byte data blocks in the
1,024-byte physical block. No header information is added to
these blocks. This consumes two bytes of space in the physical
block.
2. The CTS then places the next 340 one-byte logical blocks into the
physical block, adding two bytes of header information to each
of the logical blocks. Therefore, these 340 one-byte data blocks
consume 1,020 bytes of space in the physical block.
3. The CTS adds two gap bytes to complete the 1,024-byte physical
block.
Because of the extremely small logical block size, tape capacity is
reduced by approximately two-thirds. (342 bytes of user data stored
in each physical block out of 1,024 bytes available.)
3-14
EXB-8205 and EXB-8505
(Standard and XL)
510503
3 Implementing CTS Operations
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