High Performance Storage System

New to HPSS 8.1.0

Ordered Migration by Directory

HPSS now supports the ability to co-locate data on tape by directory. The objective is to improve tape recall efficiency. This new feature is especially pertinent when considering the use of the Full Aggregate Recall (FAR) feature released in HPSS 7.5.3.

If users organize files by directory and usually recall files from a given directory in bulk, by using Ordered Migration by Directory and Full Aggregate Recall users may see a 7x to 10x improvement in recall performance. Thus, HPSS 8.1 may be able to meet site tape-recall requirements using many fewer tape drives when compared to HPSS 7.5.3.

The migration policy will continue to honor the migration policy settings for when a file is eligible for migration, how often migration will run and the number of migration streams to use.

Prevent tape-recall events from HPSSFS Fuse

The HPSSFS Fuse mount point may now be configured to deny users from triggering HPSS tape recall events. If the nostagetape HPSSFS Fuse mount point option is specified, no data is staged from tape-only files. If the stagetape HPSSFS Fuse mount point option is specified or not included, users will trigger HPSS tape recall events for files that are not on the HPSS disk cache.

Most UNIX commands that come from Fuse are blocked, so HPSS receives one tape-recall at a time. When HPSS receives one tape-recall at a time, HPSS does not have an opportunity to organize and optimize the tape recall events. On the other hand, if a site monitors log messages, triggers can be put in place to process the error messages that are logged when the nostagetape HPSSFS Fuse mount point option is specified, and a user tries to recall a file on tape. When files are recalled in bulk, HPSS will organize and optimize the tape-recall events.

HPSS accounting information by UID and GID

HPSS will now track accounting information by UID and GID rather than by Account ID alone.

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