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Scratch Upgrade

                    Scratch Filesystem Upgrade

On Tuesday, September 6, NCSA will replace the existing scratch filesystem 
on its SGI Altix system (cobalt) with a new scratch filesystem tuned for 
better performance. The scratch filesystem includes the "scratch-global" 
directory and all batch scratch directories (accessed within a job using 
$SCR and interactively, using the "cdjob" command).

The system will be unavailable from 8 AM until 8 PM Central Time. All 
running jobs will be allowed to finish. Queued jobs will be placed on hold 
so you can ensure that any files needed in the old /scratch filesystem are 
copied to the new one before the job starts. Once you are sure the job has 
all the necessary input files, you can release the job using the command: 
qrls JOB_ID

On Wednesday, August 31, the new scratch filesystem will be available as 
/scratch-new so you can begin copying files to the new scratch filesystem. 
On September 6, the current scratch filesystem will be renamed to 
/scratch-old and the new scratch filesystem will be named /scratch.  You 
will be able to copy files from the old scratch filesystem to the new 
scratch filesystem until October 4. On October 4, NCSA will decommission 
the older scratch filesystem.

To copy a directory from one scratch filesystem to another, use the cp
command with the -r option. For example, between August 31 and September
5 you can use the following command to copy subdirectory "data" from your 
current scratch directory to the new one:

  cp -r $HOME/scratch-global/data /scratch-new/users/$USER

Between September 7 and October 3, you can use the following command to 
copy subdirectory "data" from the old scratch directory to the new one:

  cp -r /scratch-old/users/$USER/data $HOME/scratch-global
 
If you have any questions please contact NCSA's Consulting Office
at consult@ncsa.uiuc.edu or (217)244-1144.

NCSA Consulting Services
SGI Altix 3700:usr/news/Scratch_Upgrade
Last Modified: August 29, 2005