maxdsiz,maxtsiz & maxssiz

[Satish Y]

Hi Experts,

One more doubt. How is maxdsiz,maxtsiz & maxssiz related with shmmax?...
what is the formula for them?....
actually i am increasing shmmax value using following document...

http://us-support.external.hp.com/cki/bin/doc.pl/sid=53abb6901bbd43430e/screen=ckiDisplayDocument?docId=200000024645549

all kinds of answers welcomed...


Satish.

[Rita C Workman]

Hope this helps..communication is not my strongest asset.
maxdsiz = maximum process data segment size
maxssiz = maximum process storage segment size
maxtsiz = maximum process text segment size

Now shmmax is the max System Wide shared memory segment size in bytes.. Note is max system wide, so if your processes get going using their maxdsiz, etc..and they exceed shmmax value..now the system chokes and must save itself by returning an error that you have exceeded more than the system is set to give it....

I keep this bookmarked at home and on my PC at work for handy review of parms, their meaning and their formula (which you also asked about)..hope it helps you, and hope I didn't explain this badly...

http://docs.hp.com//hpux/onlinedocs/os/11i/kcparams/KCparams.OverviewAll.html

Regards,
Rita

[Bill Hassell]

It's important to note that these parameters are fences to protect from runaway of experimental programs. Setting them to a high value can allow a program to run that requires larger memory, but there are programming techniques required to allow a program to use large memory areas, especially in a 32bit environment.

For instance, a normal program cannot use more than apx 940 megs of data area or 80 megs for stack in the 32 bit versions of HP-UX. Also, large prgrams may not all fit into memory aty the same time--the good news is that HP-UX will use virtual memory and page the programs as necessary--and the bad news is that paging programs can introduce more than a 100:1 speed penalty.

Shared memory is also unique--read the memory management white paper on your system in: /usr/share/doc

[Satish Y]

Bill, Do u mean that these parameters no way related to shmmax value, but depends on requirements of programs/applications running on ur server... right?.

Satish.

[John Bolene]

Right, shared memory has nothing to do with the max sizes you mentioned.