move2silo and corresponding scripts (by Mike Johnson)
  =====================================================

            Sergey Boyarinov, Feb 2006

1. General scheme
-----------------

 bosOpen(libbosio) -> checkdisk -> checkraid -> dumpstat.short -> doublecheck x
                                             -> redalert x
                                             -> alert x
                                             -> active -> oflcpy x
                                                       -> empty -> graboldest x
                                                       -> preinsert x
                                             -> graboldest x
                                             -> move2silo -> postinsert x
                                                          -> enumoldest x
                                                          -> graboldest x
                                                          -> clonput2 ------->
                                                          -> move2silo
                                                          -> preinsert x
                                                          -> empty -> graboldest

2. Description
--------------

 Following directories and symbolic links must be created before starting:

active -> /mnt/raidX: directory contains current data from the Event Recorder

empty -> .mnt/raidX: directory is to be used by the ER after the active
                     directory fills

presilo1 -> /mnt/raidX: directory, if exists, contains data to be spooled
                        over to tape silo

postsilo1 -> /mnt/raidX: directory, if it exists, contains data most recently
                         saved to tape silo

postsilo2 -> /mnt/raidX: directory contains data which has been streamed to
                         tape silo

STUB.TARGET: file contains the name of the directory to hold stub files for
             data for the current experiment;  Stub files are later used during
             data retrieval
             example: /mss/clas/eg4a/data

logfile: log messages from various scripts

environment: for example:
set PAWNS = " `cat /ssa/PAWNS` "
set PARTITIONS = " raid0 raid1 raid2 raid3 "
set LOGFILE = "/ssa/logfile"


?????????????????????????????

KING: for example:
clon10

PAWNS: for example:
clon00
clon01
clon02
clon03
clon04
clon05
clon06

?????????????????????????????



 checkdisk: first script to be called by bosOpen(); just calls 'checkraid'
   using 'sudo'

 checkraid:  the only parameter is how much space (MBytes) may remain on disk;
   script checks the '/ssa/active' area to see if there is enough
   room for another file;  if there is not enough room, the partitions are
   juggled to make room and processes are spawned to move data to silo
   later;  If there is enought room, the script simply exits

+ dumpstat.short: return partitions list as following:
raid0 ACTIVE
raid1 EMPTY
raid2 EMPTY
raid3 EMPTY
   possible status:
ACTIVE
EMPTY
MOVING
FULL '(BACKED UP)'
FULL '(NOT BACKED UP)'

 empty: if '/ssa/empty' does not exist, grabs oldest 'postsilo' and makes
        it empty; checks again if '/ssa/empty' exists and cleans it up;
        then if '/ssa/active' does not exist mv 'empty' to 'active'

+ graboldest: return file name with biggest number, for example if
             '/ssa/postsilo1' and '/ssa/postsilo2' are exists, then
             'graboldest postsilo' will return '/ssa/postsilo2'

 active: do following actions:
         - mv '/ssa/active' to '/ssa/presilo'
         - call 'oflcpy'
         - calls 'empty'
         - calls 'redalert' if '/ssa/active' did not shows up after 'empty'
         - calls 'empty' again to clean another partition if needed
         - calls 'preinsert presilo'




+ alert: dummy right now; suppose to send warnings

 redalert: sends error message

 clonput2: calls Computer Center script; our responsibility ends here

+ doublecheck: checks to see if all files in ARG[1] have matching, nonzero stubs
              in the dir indicated in '/ssa/STUB.TARGET'; for example command
       doublecheck raid1 `cat /ssa/STUB.TARGET`
              will check if all files from raid1 were successfully transfered
              to SILO directory specified in '/ssa/STUB.TARGET'

+ enumoldest: returns the number of 'oldest' file in '/ssa' with specified name;
             for example if 'postsilo1' and 'postsilo2' files are in '/ssa'
             directory then command 'enumoldest postsilo' will return 2

 move2silo: main work is done here;

 oflcpy: copies all files '/ssa/presilo/stage_in/clas_[0-9]*.A00' into work disk

+ postinsert: move file X -> XN, where N is maximum existing N + 1; for example if
             we have 3 files 'postsilo', 'postsilo1' and 'postsilo2' then command
             'postinsert postsilo' will rename 'postsilo' to 'postsilo3'

+ preinsert: rotate group of files X->X1, X1->X2, ...; for example if we have 3
            files 'postsilo', 'postsilo1' and 'postsilo2' then command
            'preinsert postsilo' will move files as following:
                postsilo  -> postsilo1
                postsilo1 -> postsilo2
                postsilo2 -> postsilo3