DEADLOCK

Deadlock Recovery-
Abort all deadlock processes and release resource - too drastic - will lead to loss of work
Abort one process at a time - releasing resources until no deadlock How do we determine which process to abort first ? - priority ordering, process which has done least work
Selectively restart processes from a previous checkpoint i.e. before it claimed any resources difficult to achieve - sometimes impossible
Successively withdraw resources from a process and give to another process until deadlock is broken. How to choose which processes and which resources ?
1.Complex decisions due to the large number of processes present within a system
2.Difficult to automate
3.Use Operator to resolve conflicts - BUT this requires the operator to have skill and understanding of what processes are actually doing