memory allocation limit on HP-UX 11

[Moshe Libenson]

Hi,
i'm running HP-UX 11.00 on a machine with 4 cpu's and 4GB Ram (and 5GB of swap).
the system can only allocate ~700MB as a chunk.
i need to laocate a lot more then that to one process.
how do i change the limit?

[eran maor]

Hi Moshe

you need to check kernel param to have more then this chunk of info .

maxswapchunks
maxswapchunks sets the maximum amount of swap space that can be configured, system-wide.

maxdsiz and maxdsiz_64bit
maxdsiz and maxdsiz_64bit specify the maximum data segment size, in bytes, for an executing process.

maxssiz and maxssiz_64bit
maxssiz and maxssiz_64bit set the maximum dynamic storage segment (DSS) size in bytes

maxtsiz
maxtsiz specifies the maximum shared-text segment size in bytes


the param that you need to change it maxdsiz
but i didnt see the info about your kernel param.

please also see the link for info about kernel params : http://docs.hp.com//hpux/onlinedocs/os/KCparams.OverviewAll.html

[Bill Hassell]

For a standard process, you can allocate up to 940 megs as a data area using system calls like malloc. This assumes you have adjusted the kernel fence called maxdsiz to at least 940. NOTE: it is a fence and not a magic enabler for your programs. If you set maxdsiz to 1800 megs, your program cannot request more than 940 until the program is changed to use EXEC_MAGIC.

If this is a shared memory area, there are a different set of rules and kernel parameters that you will need to adjust.

Before trying to use massive amounts of RAM, read the white paper in /usr/share/doc on memory managament. Note that to use all the capabilities (virtually unlimited memory addressing), your programs may have to be rewritten and certainly must be recompiled.