topic Re: Java processes and maxdsiz_64bit in Operating System - HP-UX

Java processes and maxdsiz_64bit

CarlosAMH — Thu, 05 Aug 2010 14:43:33 GMT

Hello,

I need to run Java processes that need around 12GB of memory. Currently maxdsiz_64bit is set to 4294967296, what this means?
Do I need to set it to a higher value to run these processes? In that case there is documentation for that purpose?

Additional tasks has to be performed more than change the value?
The current situation only allows me to produce little downtimes such as a complete restart of the machines.

HP-UX 11i V3 running here.

Re: Java processes and maxdsiz_64bit

muruganantham raju — Fri, 06 Aug 2010 05:25:06 GMT

Hi,
The maxdsiz_64bit represents the maximum size of data segement that a 64bit process can have in the system.

Please refer this link:
http://nixdoc.net/man-pages/HP-UX/man5/maxdsiz_64bit.5.html

You can try java -Xmx option. Please check if the following options will be useful.

Xmsn
Specify the initial size, in bytes, of the memory allocation pool. This value must be a multiple of 1024 greater than 1MB. Append the letter k or K to indicate kilobytes, or m or M to indicate megabytes. The default value is 2MB. Examples:
-Xms6291456
-Xms6144k
-Xms6m

-Xmxn
Specify the maximum size, in bytes, of the memory allocation pool. This value must a multiple of 1024 greater than 2MB. Append the letter k or K to indicate kilobytes, or m or M to indicate megabytes. The default value is 64MB. The upper limit for this value will be approximately 4000m on Solaris 7 and Solaris 8 SPARC platforms and 2000m on Solaris 2.6 and x86 platforms, minus overhead amounts. Examples:
-Xmx83886080
-Xmx81920k
-Xmx80m

HTH
Muru

Re: Java processes and maxdsiz_64bit

Dennis Handly — Fri, 06 Aug 2010 07:36:29 GMT

>Do I need to set it to a higher value to run these processes? In that case there is documentation for that purpose?

Yes: kctune maxdsiz_64bit=12*0x40000000

>The current situation only allows me to produce little downtimes such as a complete restart of the machines.

You don't need to reboot.

When you run java, besides the parms listed by Muru, you need -d64.