HP 3000 Manuals HP 3000 Manuals
Preventing New System Activity
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.