Chapter 3 System Preparation
HPSS Installation Guide September 2002 199
Release 4.5, Revision 2
❖Virtual Volume Block Size and Stripe Width - See the discussion for disk
Virtual Volume Block Size & Stripe Width.
❖Thresholds - Again, make sure that these seem reasonable. Do they match
whatever repack or tape migration scheme (if any) of the site
❖Max VVs to Write - Does this value make sense given the number of drives
available and the migration policy?
❖MigrationPolicy & Purge Policy Ids - Should be zero unless they are really do
tape migration. Just check actual policy later when we get to it.
➢Mover Device List
❖Name - For disk devices, verify that the raw/character device is being used.
For tape devices, verify that the correct file name is being used. For AIX, the
basename (e.g., “/dev/rmt1”) is usually sufficient, but on Solaris and Irix care
mustbe taken to select the correct options that are built into the name (e.g., ‘v’
= variable block size, ‘c’ = use compression, etc.).
❖Flags- Based on the admin guide, make sure the correct flags are on. Location
support should be on for most supported drives (other than StorageTek 9840
on Solaris). For Ampex, “Write TM(0) to Sync” must be on. If different than
admin guide, why?
➢PVL Drive List - Not much here – just usually verify that the addresses seem
reasonable and that the drives are unlocked (although locked usually just means
they were being used for something else at the time lshpss was run…).
➢Server List - Overall, just make sure there aren’t extra “test” entries lying around
thatdon’t need to be. The one server whose default thread count is usually too low
is the tape storage server. If it is less than the maximum number of possible
requests(client I/O and/or migrations & stages depending on the COS/hierarchy
configurations – need to look at the BFS server-specific configuration to get the
maximum threads allowed for these activities in the BFS), then there will be the
possibility of a deadlock – as all the tape SS threads could be tied up waiting for
tape mounts and there is no thread to handle a tape mount notification callback
from the PVL.
➢Mover List
❖Buffer Size - Typically this is left at the 1MB default value. In some cases a
smaller value is justified (I don’t recall a site running in production with a
value of less than 512KB, but it is certainly possible) if memory on the Mover
nodes is tight for the anticipated workload. A larger value may be justified if
required for performance – usually on the device side (I believe the Ampex
drives run best with a 4 or 8MB buffer size).
❖Port Range - This is typically unused, so the values will be zero. This feature
allows a site to define the TCP/IP port that the Mover will bind to on its
machinefor all its client communication. This is required at some sites to allow
Mover traffic to be sent through a firewall, as only a set range of ports are
allowed.