Fujitsu MAM3184MC/MP Product/Maintenance Manual page 52

Automatic alternate block allocation is made only once during the
execution of one command. If second defective block is detected, the
alternate block assignment processing for the first defective block is
executed but the alternate block assignment processing for the
second one is not executed and the command being executed
terminates. However, the initiator can recover the twice error by
issuing the same command again.
When an error is detected in a data block in the data area, recovery
data is rewritten and verified in automatic alternate block allocation
during the execution of the READ or READ EXTENDED command.
Alternate block allocation will not be made for the data block if
recovery is successful.
Example: Even if the data error which is recoverable by the WRITE
3 - 16
IMPORTANT
LONG command is simulated, automatic alternate block
allocation will not be made for the data block.
C141-E134-01EN