    NAME
         checkpoint - Grid Engine  checkpointing  environment  confi-
         guration file format

    DESCRIPTION
         Checkpointing is a facility to save the complete  status  of
         an  executing program or job and to restore and restart from
         this so called checkpoint at a later point of  time  if  the
         original  program  or job was halted, e.g.  through a system
         crash.

         Grid Engine provides various levels of checkpointing support
         (see  sge_ckpt(1)).  The checkpointing environment described
         here is a means to configure the different types  of  check-
         pointing  in  use  for  your  Grid  Engine  cluster or parts
         thereof. For that purpose  you  can  define  the  operations
         which have to be executed in initiating a checkpoint genera-
         tion, a migration of a checkpoint to another host or a  res-
         tart  of  a  checkpointed application as well as the list of
         queues which are eligible for a checkpointing method.

         Supporting different operating systems may easily force Grid
         Engine  to  introduce  operating system dependencies for the
         configuration of the checkpointing  configuration  file  and
         updates  of the supported operating system versions may lead
         to frequently changing implementation details. Please  refer
         to the file <sge_root>/doc/checkpointing.asc for more infor-
         mation.

         Please use the -ackpt, -dckpt, -mckpt or -sckpt  options  to
         the  qconf(1)  command  to manipulate checkpointing environ-
         ments from the command-line or use the corresponding qmon(1)
         dialogue for X-Windows based interactive configuration.

    FORMAT
         The format of a checkpoint file is defined as follows:

      ckpt_name
         The name of the checkpointing environment. To be used in the
         qsub(1)  -ckpt  switch or for the qconf(1) options mentioned
         above.

      interface
         The type of checkpointing to be used. Currently, the follow-
         ing types are valid:

         hibernator
              The Hibernator kernel  level  checkpointing  is  inter-
              faced.

         cpr  The SGI kernel level checkpointing is used.

         cray-ckpt
              The Cray kernel level checkpointing is assumed.

         transparent
              Grid Engine assumes that the jobs submitted with refer-
              ence  to this checkpointing interface use a checkpoint-
              ing library such as provided by the public domain pack-
              age Condor.

         userdefined
              Grid Engine assumes that the jobs submitted with refer-
              ence  to  this  checkpointing  interface  perform their
              private checkpointing method.

         application-level
              Uses all of the interface commands  configured  in  the
              checkpointing  object  like  in  the case of one of the
              kernel level checkpointing interfaces (cpr,  cray-ckpt,
              etc.) except for the restart_command (see below), which
              is not used (even if it  is  configured)  but  the  job
              script is invoked in case of a restart instead.

      queue_list
         A comma separated list of queues to which checkpointing jobs
         belonging  to  this  checkpoint  environment have access to.
         Alternatively the keyword "all" can be used to  give  access
         to all queues across the cluster

      ckpt_command
         A command-line type command string to be  executed  by  Grid
         Engine in order to initiate a checkpoint.

      migr_command
         A command-line type command string to be  executed  by  Grid
         Engine  during  a  migration of a checkpointing job from one
         host to another.

      restart_command
         A command-line type command string to be  executed  by  Grid
         Engine  when  restarting  a previously checkpointed applica-
         tion.

      clean_command
         A command-line type command string to be  executed  by  Grid
         Engine  in order to cleanup after a checkpointed application
         has finished.

      ckpt_dir
         A file system location to which checkpoints  of  potentially
         considerable size should be stored.

      queue_list
         Contains a comma or blank  separated  list  of  queue  names
         which  are  eligible for a job if the checkpointing environ-
         ment was specified at the submission of the job.

      ckpt_signal
         A Unix signal to be sent to a job by Grid Engine to initiate
         a checkpoint generation. The value for this field can either
         be a symbolic name from the list produced by the  -l  option
         of  the kill(1) command or an integer number which must be a
         valid signal on the systems used for checkpointing.

      when
         The points of time when checkpoints are expected to be  gen-
         erated.  Valid values for this parameter are composed by the
         letters s, m, x and r and any combinations  thereof  without
         any  separating  character  in between. The same letters are
         allowed for the -c option of the qsub(1) command which  will
         overwrite the definitions in the used checkpointing environ-
         ment.  The meaning of the letters is defined as follows:

         s    A job is checkpointed, aborted and if possible migrated
              if  the  corresponding sge_execd(8) is shut down on the
              job's machine.

         m    Checkpoints   are   generated   periodically   at   the
              min_cpu_interval  interval  defined  by  the queue (see
              queue_conf(5)) in which a job executes.

         x    A job is checkpointed, aborted and if possible migrated
              as  soon as the job gets suspended (manually as well as
              automatically).

         r    A job will be rescheduled (not checkpointed)  when  the
              host  on which the job currently runs went into unknown
              state and the  time  interval  reschedule_unknown  (see
              sge_conf(5)) defined in the global/local cluster confi-
              guration will be exceeded.

    RESTRICTIONS
         Note, that the functionality of any checkpointing, migration
         or  restart  procedures  provided  by  default with the Grid
         Engine distribution as well as the way how they are  invoked
         in the ckpt_command, migr_command or restart_command parame-
         ters of any default checkpointing environments should not be
         changed  or  otherwise  the  functionality  remains the full
         responsibility of the administrator configuring  the  check-
         pointing  environment.   Grid  Engine will just invoke these
         procedures and evaluate their exit status. If the procedures
         do  not perform their tasks properly or are not invoked in a
         proper fashion, the checkpointing mechanism may behave unex-
         pectedly, Grid Engine has no means to detect this.

    SEE ALSO
         sge_intro(1),  sge_ckpt(1),  qconf(1),   qmod(1),   qsub(1),
         sge_execd(8).

    COPYRIGHT
         See sge_intro(1) for a full statement of rights and  permis-
         sions.