DSS/Db Backups/HSM Overview

David Wolfe

DSS-I

• 102 CD ROM set– POSS-I red XE plates – SERC-J blue S plates– Compressed ~10X– http://archive.stsci.edu/cgi-bin/dss_form

DQVS

• Palomar Quick-V– GSC-I construction plates– 39 CD ROM set– Compressed ~10X– http://archive.stsci.edu/cgi-bin/dss_form

XDSS

• RED ( III-aF)– POSS-II XP images

• Completed 897 out of 897, 100%– UK Schmidt XS images

• Completed 592 out of 606, 98%– UK Schmidt ER images

• Completed 270 out of 288, 94%– Compressed ~10X– Contained on Volumes 0001-0390– Completed by end of 2000– http://archive.stsci.edu/cgi-bin/dss_form

XDSS(cont)• BLUE (III-aJ)

– POSS-II XJ images• Completed 897 out of 897, 100%• Contained on Volumes 1001-1226

• INFRARED (IVN)– POSS-II XI images

• Completed 340 out of 897, 38%• Contained on Volumes 2001-2084

– UK Schmidt IS images• Completed 151 out of 894, 16%• Contained on Volumes 3001-3043

– Compressed ~10X– Completed by mid 2001, telescope limited– http://archive.stsci.edu/cgi-bin/dss_form

XDSS(cont)

• Headers– Headers for all XDSS second generation scans

• ftp://ftp.stsci.edu/software/casb/xdss/

DB BACKUPS

• DataBase about 1TB• How to handle such a large volume

– Old method• Stand alone DLT drive, NT Backup• 9-10 hours per tape• 15+ tapes

DB BACKUPS (cont)

• New method– BackupExec by Veritas

• DLT jukebox, 8 cartridges• Breakup into North and South• High through put• Less user interaction

DB BACKUPS (cont)

• Importance of the Backups– Large system, just in case of errors– Already had to use previous backups

• Replaced corrupted files– Time Frame

• Plans are for monthly– Minimal impact to production

HSM

• Hierarchical Storage Management– DiskXtender by OTG

• Large storage by using DLT jukeboxes– 2 - 46 DLT tape jukeboxes– ~60GB/tape

– Storing processing data• OOP, cutouts, deblend, rank…

HSM (cont)

• Ease of retrieval– All files visible from explorer– Right click on file to retrieve

• Limited by physical disk space