Conference humane::scheduler

1112.0. "Scheduler Hangs when Master Drops out of Shadow Set" by COMICS::SUMNERC (OpenVMS Counter Intelligence) Mon Jun 03 1996 14:14

                                                                
    
    		Scheduler Hangs when Master Drops out of Shadow Set
    		===================================================
      
    
    
    Hi,
    
    I have a a cutsomer with the following problem and I am wondering if
    anyone can help....?
    
    Customer has
    
              +----[DIA30] on bus D0  (MASTER)  }
              |          SCSI disks             } SHADOW SET
              |   +---[$DIA4] on bus A4         }
              |   |
            +-+---+-+
            | Alpha |
            |OpenVMS|
            |V6.2   |
            |       |
            |Sched  |
            |2.1B   |
            +-------+
    
    
    My customer says that when his MASTER disk from his shadow set leaves
    the Shadow set (for whatever reason), scheduler "hangs".  My customer
    explained that jobs finish, but their status in scheduler doesn't change. 
    He is able to use scheduler and the process in fine, but nothing is 
    updated or changed, no jobs can be created, no logs or status's change.
    
    Customer has ALPSHAD10_061 om his system.
    
    
    I have asked the customer to provide the following information next
    time we see the problem.
    
    o Status of process.
    o SDA SHOW PROCESS/CHANNELS (see what disk it's looking at).
    o Check logs of scheduled jobs.
    
    
    
    Does anyone have any other ideas of what I could ask ?
    
    Thanks in advance for any help on this one (I'm baffled).
    
    Chris Sumner
    OpenVMS Support, UK CSC, Basingstoke 7833 3667
    

    If you do "$ sched show status"   during this hang, what do you see?
    (this shows the order of schedulers waiting for the "default" lock. If
    it hangs, something is wrong there)
    
    Does the DCL user interface hang when you try to  $sched modify <job>
    while it is in this state ? (if not, shows another set of locks is ok)

    Scheduler is not currently hung, I'll update the conference as soon as
    he gets this state again.
    
    Thanks,
    
    Chris.