Disk Space on the Central System (dØmino)

• User space  :   Each user account receives a default allocation of 67.5 MB space
  in the /home/<user> area.    Requests for an increased allocation, WITH JUSTIFICATION,
  should be sent to helpdesk@fnal.gov,  marked attn: d0-primary.   This space is regularly
  backed up by system management.   It is NOT the right storage place for large data files.
  
  
• Scratch space :  There are four scratch areas, and each user has a directory automatically
  created in all four.   These are organized by how long files remain before the cleanup 
  program automatically deletes them.  The areas are named /scratch/1/,  /scratch/4/, 
  /scratch/10/, and /scratch/14/  -  the files remain for 1, 4, 10, and 14 days respectively.
  Evading the automatic deletion algorithm is anti-social behavior, and you should expect
  your files to disappear immediately if such evasion is discovered.
  
  
• tmp space (/usrdisk/) :  Each institution may have, on request, an allocation of 
  approximately 50 GB of space on the /usrdisk file system.  Send requests to  Nick Hadley  
  You can check the current allocations at  this link.   This space is not backed up by 
  system management.
  
  
• project space :  ID groups, physics groups, and other projects defined by the 
  experiment management receive disk allocations by request, from the Offline 
  Resources Board  (email  Nick Hadley ).   You can check the current allocations 
  at  this link.   This space is not backed up by system management.
• sam cache :  For the present, the sam cache is best utilized by running all projects
  under the dzero group.   The cache is not currently divided up except for certain very 
  small special purpose allocations (for example, the algo group cache for reco certification 
  samples).    The dzero cache contains 10 TB -- using this cache, the thrashing of files
  should be minimized.    If you run projects with many files through a very small cache 
  such as demo or test, you will always be reading your files from tape and not making 
  optimal use of the disks.    [Note:  you can define your datasets using a different group,
  to aid in organizing dataset names, but run the projects using group dzero.]