Storage Unit Management System - SUMS

SUMS "owns" JSOC's data storage resources. It manages the disk space available for storing data, it manages the tape systems, and it tracks the current on-line location of data being stored for the JSOC. SUMS is implemented as a server program and management utilities. The SUMS server uses tables in the JSOC PostgreSQL database to track what we call "Storage Units". A Storage Unit is simply a directory and its subdirectories, if any.

SUMS gives each managed storage unit a SUMS identification in the form Dxxxxx where xxxxx is a serial number. SUMS allocates disk space on one of the SUMS owned file systems, creates a directory named e.g. /SUM5/D12345 and provides the directory name and SUMS ID (e.g. D12345) to the requesting program.

The requesting program tells SUMS how long to keep the data online and whether or not to archive it on tape. The SUMS disks are configured in a RAID system and should provide secure storage online so that only the most valuable or largest collections of data need be archived to tape.

The requester also tells SUMS the name of the data series that the storage unit belongs to and the SUMS data collection that that series belongs to (default to JSOC but can be e.g. DSDS). The requester also tells SUMS a tape storage group that the series belongs to. SUMS will group storage units for a given series onto tapes assigned by tape group number. This keeps data for related series on a well defined set of tapes.

SUMS requirements and implementation will eventually be described in the JSOC Data Processing Plan.

The SUMS programmer's interface is described at SUM_API.html.