NCAR/CISL/SCD User Forum

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NCAR/CISL/SCDUser Forum

• Using the Mass Store Subsystem
• Efficiently
• May 19, 2005
• Mike Page
• Consulting Services Group
• mpage_at_ucar.edu

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Efficient Usage

• NCAR\
  Users
• CISL\
• SCD

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NCAR Mass Store Subsystem(MSS)

• Currently stores two petabytes of data
• Library of Congress (printed collection)
• 10 Terabytes
• Mass Store holds 200 Library of Congress
• Data holdings increasing exponentially
• 1986 - 2 Tb
• 1997 - 100 Tb
• 2002 - 1000 Tb
• 2004 - 2000 Tb

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NCAR Mass Store Subsystem Capacity vs. Demand

• Planning, planning, planning
• CSG/MSSG assistance available
• Is it a file server?
• Recommended file sizes
• Recommended volume of metadata operations
• Other keys to efficient usage
• Be selective in the data stored on the MSS
• Avoid repetitive reads/writes
• Choose class of service and retention periods
• according to value of data

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File purge policies

• If
• you are no longer active on any project
• your project closes
• you are no longer employed by UCAR/NCAR
• you are doing periodic maintenance of your MSS
  files
• You can
• delete your MSS files yourself
• request that the SCD delete your files
• change the project number to an active account
• transfer ownership of the files to another user
• transfer the data between the MSS and other
  media
• 1 Terabyte gt 300 DVDs
• transfer data to another network location

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How to access information on your MSS
holdingshttp//www.scd.ucar.edu/docs/mss/MSSholdi
ngs.html
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MSS Summary Report
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Summaries
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Class of Service
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Mass Store Access from Command Line and Batch
Scripts

• msread
• msread -eof -f fmt -l n -nomail
  -noretry -nowait \
• -nowarn -R -r rpass -u usrnm loc_flnm
  MSS_flnm
• mswrite
• mswrite -C cos -c cmnt -eof -f fmt -l
  n -m n \
• -nomail -noretry -nowait -P proj_num -r
  pass \
• -t n -v vmn -w pass loc_flnm MSS_flnm
• msrcp
• msrcp -async -class cos -noreplace
  -period n \
• -project proj_num -rpwd rpass -wpwd wpass -R
  -Version \ source_file source_file... target

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MSS Access from User Applications

• f90 -L /usr/local/lib -l mss test.f
• msread - retrieve file from mass store and make
  it local
• mswrite - write local file to mass store
• msrecall - wait for specific async read/write to
  complete
• mswait - check status of all queued async
  reads/writes to complete
• mserror - get error messages for last failed
  read/write

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The End