Spooling refers to putting jobs in a buffer,a special area in memory or on a disk where a device can access them when it is ready.Spooling is very useful because the device can access data at different rates.
Spooling is one of the component of Batch systems.In spooling the buffer provides a waiting station where the data can rest while the slower device catches up.
Spooling is an acronym for simultaneous peripheral operation on line.Spooling uses the disk as a large buffer for outputting data to the printers and to the other devices.
Normally computer can perform the IO in parallel with computation,then it becomes possible to have the computer to read a deck of cards to a tape,drum or disk and to write out to a tape printer while it was computing.This process is called Spooling Process.
The most commonly used spooling application is Print Spooling.In Print spooling,the documents are loaded into a buffer and then the printer pulls them off the buffer as its own rate.
You can also check Printer spooler in your computer,if it is stopped you can't print any document.To check it is running or stopped.Goto run and type msconfig and press enter.In the window select services tab and check it.
Spooling is also used for the processing of data at the remote sites.
The CPU sends the data via communications path to the remote printer.Spooling overlaps the IO of the one job with the computation of other.
Advantages Of Spooling:
* The spooling operation uses a disk as a very large buffer,so it is very useful to send large data.
* Spooling is however capable of overlapping IO operation of one job with processor operations for another job.
Disadvantages Of Spooling:
* The main disadvantage of Spooling is that it is very difficult to debug.
* Due to lack of prtection scheme,one batch job can affect the pending jobs.
Spooling is very useful concept and i think this article is very useful for OS Students.