Hub/Switch Installation Guide

Chapter 7 HPSS User Interface Configuration
452 September 2002 HPSS Installation Guide
Release 4.5, Revision 2
Innormaloperation,onlyalarmandeventmessagesneedtobeenabled.Traceanddebugmessages
should be enabled when it is necessary to track down the root cause of a problem. Logging too
many different types of messages will impact HDM performance.
MainLogName specifies thenameofthefile usedfor themaineventlog.Typically, thiswill be/var/
hpss/hdm/hdm<id>/hdm_main_log.Thisfile containsarecordof allname spaceeventsforwhich
processing has notyet completed.The file must exist before the HDM is started, butcan beempty.
If MainLogSize is changed, HDM automatically adjusts the size of the file as needed. This log is
veryimportantandshould bestoredona reliabledisk.Also, sincethe file isfrequentlyupdated by
HDM, it should be stored on a low latency disk.
MainLogSize specifies the total number of name space events that can be handled concurrently.
While an event is being processed, information about the event is stored in a log file. When HDM
restarts after a crash, it reads the log to determine what must be done to synchronize the DFS and
HPSS name spaces. If too small a value is chosen for the log size, HDM may occasionally have to
waitfor alog entryto becomeavailablebeforeitcanprocessa namespace event.Thereis noreason
toselectavaluemuchlargerthanNumNamespProcesses.Avaluebetween10-25isagoodstarting
point.Ifnecessary,thevalueofthisparametercanbedecreasedbyeditingconfig.dat andrestarting
HDM.However,thisonlyworks ifthe newvalueofMainLogSize is largeenoughtoaccommodate
all of the outstanding events in the old event log. The name of this log file is specified by
MainLogName.
If both the event log and event queue become full, event processing can not be done, and HDM
will return an error to the DFS SMT.
MaxFilesets specifies the maximum number of filesets HDM can support. The number must be at
leastaslargeasthenumberoffilesetsonthedmlfsaggregatesatthesite.Alargervaluecanbeused
ifaddingnewfilesetsisanticipated.However,usingavaluethatistoolargeaddsoverheadtoevent
processing. For XFS, the value of this parameter should be identical to the value defined for
MaxFileSystems.
MaxFileSystems specifies the maximum number of DFS aggregates or XFS filesystems the HDM
can support. For DFS, this number must be at least as large as the number of dmlfs aggregates on
the DFS File Server. A larger value canbe used if adding new aggregates is anticipated.For XFS, it
should be large enough to accomodate the planned number of XFS filesystems, and MaxFilesets
must be set to the same value. If the value must be changed, HDM must be restarted before the
change takes effect.
MaxGateways determines themaximumnumber ofentriesallowed inthegateways.dat. Sinceitis
recommended to have two entries for each DMG (one with the short name and one with the fully-
qualified name) and one entry for each administrative machine, this value should be at least 3. If
this value is too small, the HDM will not start, so try to use the same number as there are lines in
the gateways.dat.
MaxMsgFileSize specifies the maximum size in bytes of the message log files. When writing to a
log file will exceed this size, the message logger automatically switches to the other log file. If the
value for MaxMsgFileSize is too small, potentially useful information will be lost as older
messages are overwritten with new ones. A good starting value is 5000000.
MaxPolicies specifies the maximum number of migration and purge policies that can be handled
byHDM.Thevalueshouldbelargeenoughtoaccommodateallofthepurgeandmigrationpolicies
defined in policy.dat. (There is no need to make this value larger than the sum of these policies.)