You control the number of executing jobs and sessions with two commands,
LIMIT and JOBFENCE. The LIMIT command controls the
number of jobs or sessions that execute concurrently. (The limits you set with
the LIMIT command cannot exceed the maximum job/session limit
determined by your system configuration.)
The JOBFENCE command lets you choose the priority jobfence--a
number between 0 and 14 (inclusive). Each session and job logs on
to the system with an input priority between 1 and 13 (inclusive);
the default input priority for standard MPE users is 8. In order
for a session or job to execute, its input priority must exceed
the current jobfence.
When you set the jobfence high, jobs with an input priority
less than or equal to the jobfence enter the WAIT state. MPE XL
refuses attempts to initiate a session with an input priority that
does not exceed the current job fence. Users see the following message:
CAN'T INITIATE NEW SESSIONS NOW.
If you set the jobfence to its highest possible value, 14,
only users assigned system manager (SM) or system supervisor (OP)
capability are able to log on. (System managers and system supervisors
are the only users allowed to log on with the HIPRI parameter of the
HELLO and JOB commands.) Setting the jobfence to 14 prevents
all other users from gaining access to the system during a system
backup. Enter:
:LIMIT 0,0
:JOBFENCE 14
To check the new job/sessions limits and the system jobfence, enter:
:SHOWJOB STATUS
The last line of the message on your console should now exactly
match the example shown below:
JOBFENCE= 14; JLIMIT= 0; SLIMIT= 0
If you see anything else, you made a mistake entering the LIMIT and
JOBFENCE commands. Follow the instructions again.
NOTE: For an online backup, make sure that no one logs onto the system
while the backup is starting. Once TurboSTORE informs you that files can be
modified, via a console message, you can allow users to log on again.
For a 7x24 true-online backup, you do not have to prevent
new system activity. All normal system activity can continue during
the backup.
Even though jobs and sessions can
continue to run during both an online and 7x24 true-online backup,
it is not advised that you run processor or disk intensive jobs
during a backup. Doing so will degrade both the backup's and the
job's performance. If possible, try to schedule large jobs and backups
at different times.