IBM HPSS manual Capturing the Metadata Conversion Output

three minutes, and the subsystem conversion took approximately 40 minutes.

6.2.6.1.Running Time for the Long Running Metadata Conversion Utilities (for 4.5 upgrades only)

A system with more than 3 million HPSS files will see a significant performance gain from choosing to run the long running metadata conversion programs in parallel. With 3 million files, the serial conversion should take approximately 11 hours to finish, while the parallel conversions would take only 2 hours.

The table below lists the estimated time required for each long running conversion program to convert one million SFS metadata records in its associated SFS file. To estimate the runtime for each conversion program, divide the number of records in the appropriate SFS file by one million and then multiply by the number given in the table. The result will be the estimated number of minutes required for that conversion program to run.

Table 10. Runing Times for Long Running Metadata Conversion Utilities

HPSS 4.5 Metadata Conversion Program	Minutes per 1 million SFS Records
db_convert_bftapeseg	24
db_convert_bitfile	20
db_convert_nsobject	38
db_convert_nstext	16
db_convert_storagesegdisk	48
db_convert_storagesegtape	48

These times will vary depending on the hardware configuration of the system on which the conversion is being run. The time estimates given above were determined on a relatively inactive system (44P-270) with about 3 million HPSS files. For example, a system in which DB2 shared one disk for all tables and table spaces (the worst configuration possible) saw performance twice as slow as what is listed above. These numbers also do not take into account the extra time it will take to run the long running metadata conversion programs in parallel.

6.2.7. Capturing the Metadata Conversion Output

All conversion output should be captured and retained for problem diagnosis and verification purposes. Prior to running a metadata conversion program, consider whether or not to run the scripts with their default behavior. Progress of the conversion programs is sent to standard out. Errors from all conversion programs are sent to standard error. We recommend that each site redirect both standard error and standard out to a file and, upon completing each conversion, search for common strings associated with problems (e.g., “Error” and “Warning”). All errors and warnings should be investigated.

Some of the conversion programs output information that allows them to restart should an error occur during a conversion run. These files are stored in the /var/hpss/convert/6.2 directory. Ensure that the filesystem containing the /var/hpss/convert/6.2 directory has at least 25 MB of free disk space prior to

HPSS Installation Guide	July 2008
Release 6.2 (Revision 2.0)	185