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Chapter 3 System Preparation
HPSS Installation Guide September 2002 201
Release 4.5, Revision 2
❖ Copy Count & Skip Factor - These control multiple copies. Typically these are
set for 1 or 2 copies on tape (with a disk level at the top of the hierarchy). If not
one of these, what is the rationale?
❖ Request Count - Verify that the request counts (remember that more than one
disk SC can use the same migration policy) do not appear to make
unreasonable demands on the available tape drives – e.g., if all migrations run
at once are there enough drives to service all the migrations? Given the
workload is that scenario likely? In that case, what are the requirements for
retrieving files that must come from tape?
❖ Flags - If all flags (“FWC”) are not on, what is the rationale?
➢ Purge Policy List
❖ Last Access Interval - Again this is ideally defined by the workload – for a file
on disk, how long after it has been accessed (read, most likely) is it unlikely
that it will be read again anytime soon. Typically something like 60 minutes
seems to be reasonable.
➢ Start & Stop Space Used Thresholds
➢ Accounting Policy - None
➢ Log Policy List - Verify logging levels are reasonable. For every server other than
the Mover, that currently means “AE------ AE-“. For the Mover, add ‘D’ to enable
DEBUG logging.
➢ Location Policy List - None
➢ File Family List - None
➢ Name Server - None
➢ Bitfile Server
❖ Max I/O & Max Copy Requests - Verify that these values are reasonable given
the anticipated workload and available resources (core server power, storage
devices, etc.). As noted before, these values must be compared the thread pool
size in the tape Storage Server to eliminate the possibility of a deadlock during
heavy load.
❖ Default COS - Verify that this is a reasonable value (some sights actually use a
bogus value if they elect to not allow files to be created without specifying an
explicit COS).
❖ COS Copy to Disk - For change of COS operations, should the files be copied
to the disk level of the hierarchy or the tape level? Verify the desired setting is
correct.
❖ PVR List