Hub/Switch Installation Guide
Chapter 3 System Preparation
HPSS Installation Guide September 2002 201
Release 4.5, Revision 2
❖ Copy Count & SkipFactor - These controlmultiple copies. Typically theseare
setfor1or 2copies ontape (with a disklevelat thetop ofthe 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
unreasonabledemands ontheavailable tapedrives–e.g., ifall migrationsrun
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 theworkload – 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&MaxCopy Requests- Verifythatthesevalues arereasonablegiven
the anticipated workload and available resources (core server power, storage
devices,etc.).As notedbefore,these valuesmust becomparedthe threadpool
sizein thetape StorageServertoeliminatethepossibilityofadeadlockduring
heavy load.
❖ Default COS- Verify that this is areasonable value(some sights actually usea
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 thedisk level of the hierarchy orthe tape level? Verify the desired setting is
correct.
❖ PVR List