Dear T13 Reflector Member:
I took the task at the last meeting to define Allocation Unit, which is used in
the Configure Stream Command. The purpose of this parameter is to tell
the drive how large the contiguous regions (clusters) of data are, so the
drive can do read ahead to the end of Allocation Unit. By knowing the
size of the Allocation Units, which are expected to be large on AV systems,
the drive can keep the right size of read ahead buffer for each stream set up
with configure stream.
This is what I have for a proposed definition:
Allocation Unit Size:
Allocation Unit Size is a parameter of a Configure Stream command. Streaming
application file systems may allocate contiguous ranges of logical blocks as
file system structures. The Allocation Unit Size parameter informs the device of
the expected size of the contiguous ranges so that the device may optimize
buffer management. Setting the Allocation Unit Size does not restrict or
change command behavior.
Best Regards,
Daniel J. Colegrove
Hitachi Global Storage Technologies
[EMAIL PROTECTED]
(702) 614-6119
