There are many object types we encounter every day while working on IBM i, typically *LIB, *FILE, *DTAARA, or *PGM.

The *JOBSCD object type is far less common but it has some interesting properties. As its name implies, it contains the data of the IBM i integrated job scheduler (often called WRKJOBSCDE). There is always one and only one *JOBSCD object on any IBM i system, it is called QDFTJOBSCD and is located in QUSRSYS library.

You can’t delete, rename, duplicate, or move this object, it can only be QDFTJOBSCD in QUSRSYS.

The object can be saved and restored at will (as long as you don’t try to restore it in another library). This has two main use cases:

  • For systems with software replication of PowerHA, you can save and restore the QDFTJOBSCD object to switch them between production and backup system during a switchover.
  • Before V7R5, there was no way to suspend the scheduler while retaining the status of the scheduler individual entries. The workaround was to backup the QDFTJOBSCD object, hold all the scheduler entries with HLDJOBSCDE and restore the QDFTJOBSCD object to resume scheduling. V7R5 introduced the special value *JOBSCD in the HLDJOBSCDE command that prevents the scheduler to start any job until it is enabled with RLSJOBSCDE, all while keeping the status of the individual scheduler entries.

It is a bit surprising to see that a dedicated object type was created while being restricted to only one object per system, IBM was probably thinking about allowing multiple job schedulers one day (as hinted by David Novey in this article from 1992 when the scheduler was introduced in V2R2!). This hasn’t happened (and probably never will!).

While the integrated job scheduler is still fully supported by IBM and even saw some improvements in V7R5 (addition of the yearly schedule and the possibility to hold the scheduler without changing the entries state), it is still a very basic scheduler (as it’s intended to be). If you need more advanced functions like calendars, job dependencies, sub daily schedules, the IBM Advanced Job Scheduler (also known as JS1) is now usable for free!