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HP OpenVMS Systemsask the wizard |
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The Question is: Suppose I'm running AUTOGEN w/ feedback and reboot periodically - maybe in a self submitting batch procedure. If the load is changing (sufficiently enough between runs) will AUTOGEN then resize the pagefile up and down (the latter by recreating the pagefi le)? Is there a way to allow AUTOGEN to adjust upwards as needed but never downwards (like a high water marker) - without having to keep in synch by (manually) updating MODPARAMS.DAT? For now I think I'll have to set PAGEFILE=0 in MODPARAMS.DAT and then b ump by hand as needed (using SWAPFILES). Thanks The Answer is :
Adding the line
MIN_PAGEFILE=minimum-desired-size
to MODPARAMS.DAT should do exactly what you want. The only problem I can
forsee is that if AUTOGEN resizes the file upwards leaving your MIN_PAGEFILE
value less than the actual pagefile size, AND the difference is more than
10% AND your usage drops, AUTOGEN may reduce the filesize to somewhere
between the current value and the declared minimum. If you see this as a
problem you could have a periodic job that sets MIN_PAGEFILE to the size
of the current pagefile. Perhaps the simplest way would be using an
"include" file.
For example, in MODPARAMS.DAT
AGEN$INCLUDE_PARAMS SYS$SYSTEM:MINPAGEFILE.DAT
Your code to update the pagefile could look like:
$ OPEN/WRITE out "SYS$SYSTEM:MINPAGEFILE.DAT"
$ size=F$GETSYI("PAGEFILE_PAGE")*F$GETSYI("PAGE_SIZE")/512
$ WRITE out "MIN_PAGEFILE=''size'"
$ CLOSE out
Note that this creates a file in the SYS$SPECIFIC root.
If you want to ensure that this (or any other action) occurs prior to any
execution of AUTOGEN, you could create your own MYAUTOGEN.COM, for example:
MYAUTOGEN.COM
$ OPEN/WRITE out "SYS$SYSTEM:MINPAGEFILE.DAT"
$ size=F$GETSYI("PAGEFILE_PAGE")*F$GETSYI("PAGE_SIZE")/512
$ WRITE out "MIN_PAGEFILE=''size'"
$ CLOSE out
$ @SYS$UPDATE:AUTOGEN.COM "''p1'" "''p2'" "''p3'" "''p4'" "''p5'" -
"''p6'" "''p7'" "''p8'"
Although the Wizard cannot recommend it, some customers have been known
to rename the real AUTOGEN.COM (or SHUTDOWN.COM etc...) and replace it
with a shell like the above to enforce a site policy. For example
$ RENAME SYS$COMMON:[SYSUPD]AUTOGEN.COM SYS$COMMON:[SYSUPD]REAL_AUTOGEN.COM
SYS$COMMON:[SYSUPD]AUTOGEN.COM
$ OPEN/WRITE out "SYS$SYSTEM:MINPAGEFILE.DAT"
$ size=F$GETSYI("PAGEFILE_PAGE")*F$GETSYI("PAGE_SIZE")/512
$ WRITE out "MIN_PAGEFILE=''size'"
$ CLOSE out
$ @SYS$UPDATE:REAL_AUTOGEN.COM "''p1'" "''p2'" "''p3'" "''p4'" "''p5'" -
"''p6'" "''p7'" "''p8'"
The danger is you will need to manage updates very carefully to ensure
that the correct files are returned to the correct places and updated
correctly.
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