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End of Tape (EOT) or End-of-Partition (EOP)
Recoverable Data Error
Unrecoverable Data Error
Incorrect Length
When the end-of-tape or end-of-partition position is encountered, the command
terminates with a Check Condition and Medium Error (03h) sense key. The Valid bit
(byte 0, bit 7) and the EOM bit (byte 2, bit 6) are set.
The Residual Length field is then set as follows:
•
If the Fixed bit is 1, it equals the difference between the CDB transfer length and
the number of actual blocks read.
•
If the Fixed bit is 0, it equals the CDB transfer length.
The logical position after encountering an end-of-tape or end-of-partition error is
undetermined.
If an error is encountered while reading the drive applies its retry algorithms. If the
retry algorithm reread attempts fail the error is considered unrecoverable and is
reported as such.
If an Unrecoverable Data Error is encountered, the READ command terminates with
Check Condition and a Medium Error (03h) sense key.
If the Valid bit (byte 0, bit 7) is set, Residual Length field equals the difference
between the requested Transfer Length and the actual number of blocks or bytes
transferred. On termination, the tape is positioned after the error block on the EOT
side of tape.
Writing fixed- and variable-length blocks varies according to the setting of the Fixed
bit.
When the Fixed bit is set (1), one or more tape blocks can be read. The CDB
Transfer Length field specifies the block count to read. The block size is the current
block size of the drive, which is set to 512 at power-up or after a SCSI Bus Reset.
The host can change the current block size by issuing a MODE SELECT command
with a new block descriptor parameter that specifies a new block size. If the current
block size differs from the actual block size of the block being read, the drive reports
an Incorrect Length error.
When the Fixed bit is reset (0), the CDB Transfer Length field indicates the number
of bytes to be read. When the actual block size found on tape differs from the CDB
Transfer Length, an Incorrect Length error is reported.
LTO SCSI Interface Manual
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