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