Provided are a method, system, and article of manufacture, wherein a
primary storage control unit receives an information unit from a remote
host over a fiber channel connection, wherein persistent information unit
pacing is implemented over the fiber channel connection. Information is
maintained on how many large writes have been received at the primary
storage control unit over at least one logical path established over the
fiber channel connection between the primary storage control unit and the
remote host, wherein a large write is an input/output (I/O) operation for
which a number of data information units that are processed exceeds a
default value of an information unit pacing credit. The primary storage
control unit adjusts an information unit pacing parameter included in a
response sent from the primary storage control unit to the remote host,
wherein the adjusting is based at least on the information maintained on
how many large writes have been received at the primary storage control
unit over the at least one logical path.