Parallel
resources are generally accessible through reservation systems, also
called batch systems. To execute their jobs, clients have to submit via
special mnemonics and chosen options a script that contains the command
line that launches the job. Options are not necessarily given in the
submission line, but can also appear in the script with a correct
syntax. Several batch systems exist. Among them, one can cite Loadleveler on IBM resources, OpenPBS or Torque , which are forks of the well-know PBS system, and OAR developped by IMAG at Grenoble, and used in the Grid'5000 Project of a research grid. Most of the submitted jobs are parallel jobs, coded from the MPI standard with an instantiation like MPICH or LAM.In
order to correctly use a batch system, a client must provide in the
submission line or in the script several information like: The number
of machines to assign, the duration that they will be used, the number
of MPI processes to use (indeed, most applications still use MPI-1.2
implementations where the number of processes is statically defined at
the spawning of the jobs).

Early computers were run from console. The card readers and tape drives were input devices. Line printers, tape drives and card punched were common output devices. The user did not interact directly with computer system. The user prepared a job that consisted of program, data and some control information (control cards). He then submitted it to the computer operator in the form of punched cards.

The operating system was simple. Its basic job was to transfer control automatically from one job to the next. The operating system was always resident in memory. The operator .batched similar jobs together and then ran in the computer to speed up the processing.
The CPU is often idle in this environment as speed of I/O devices is much slower than CPU. Alter sometime, the introduction of disk instead of card reader resulted in faster I/O devices.

In disk technology, the operating system keeps all jobs on a disk instead of card reader. The resources are utilized and jobs are performed more efficiently with the help of job scheduling. Job scheduling is possible because all jobs are present on the disk.
The memory contains operating system in one part and user program in other part. The user space can contain only one process at a time in batch systems. Digital equipment's VMS is an example of a batch operating system.

Simple Batch Systems

• Sequence jobs and transfer control automatically from job to
  job.
  

  
  
  • Saves setup time for jobs.
    

• Monitor the current job.
  

  
  
  • Resource consumption.
    

• Device drivers.

  
  

Operating

System

User

Program

Memory Layout