Chapter 3 System Preparation
200 September 2002 HPSS Installation Guide
Release 4.5, Revision 2
❖ControlHostname & Data Hostname - The control hostname should reference
thenetwork interface over which the requests are sent from the SS and PVL to
the Mover. It is typically an ethernet address (although this is certainly not
required), since that is a reasonably low-latency network and this interface
does not require very much bandwidth.
The data hostname is used by the passive side Mover (the disk side for an
intra-HPSStransfer between disk and tape, and the read side for disk-disk or
tape-tape), when it creates a listen port for the actual data. This is typically a
higher bandwidth interface than the control hostname – usually something
like gigabit ethernet, HiPPI or the SP switch. Note that this setting has no
bearing on Mover to client transfers, as the network interface on the Mover
used for that transfer is solely determined by the operating system’s routing
table based on the client address.
❖Executable Name - Verify that the named executable supports the specific
optionsthat are required for this Mover. On the device end, make sure that the
correct device driver interface is enabled (e.g., _ssd for the IBM Atape driver
for 3490E/3590/3580, _omi for the Greshem/OMI driver for StorageTek
drives, _dd2 for Ampex DST drives, _bmux for the IBM BMUX attached
3490s). On the client side, make sure that the correct client access mechanism
is enabled (e.g., _gpfs for local file support).
❖EncryptionKey Set - This is not critical – but the encryption key should be set.
This should ensure that there is proper security placed on the TCP/IP
connection to the Mover (the one used by the SS and PVL).
➢Migration Policy List
❖Runtime interval - Verify that this is a sane value. In most cases, for disk
migration you don’t want this to be going off 5 minutes after the last run
completed – nor do you likely want it not going off for 5 days. For tape
migration, a larger value is likely more appropriate (but we don’t have much
experience here at a production site…).
❖LastRead Interval (tape) - This should ideally be based on the workload – how
longafter a file has been read is it quite unlikely to be accessed again? Since we
don’treally get this level of understanding very often and since we don’t have
anyreal experience – I would hazard a guess that a much larger value than the
“Last Update Interval” for disk would be appropriate.
❖Last Update Interval (disk) - This should ideally be based on the workload –
how long after a file has been written is it quite unlikely to be written again?
Since we don’t really get this level of understanding very often, some other
ruleof thumb is typically used – I think 30 or 60 minutes is usually reasonable.
Alower value might be used if a site is concerned about getting a tape copy of
thedata sooner after the data is written (worst case is that we might need to re-
migrate the data later – if it is subsequently updated).
❖TargetFree Space - If this is not 100%, why not? For a disk migration, one goal
isto get the data backed up to tape so in general we should migrate every file
that meets the other migration criteria.