topic Re: maxdsiz 64 bit in Operating System - HP-UX

maxdsiz 64 bit

Andrew Luis Arruza — Fri, 10 May 2002 17:28:59 GMT

HP-UX 11.0
Manugistics told our developers that I can set the maxdsiz to a -1 which would disable all limits and allow the system to allocate memory as it want.
I am NOT able to set maxdsiz_64bit to a -1.
Has anyone been able to do this or can you give me any suggestions.
As always, point will be assigned.
Thanks, Andy

Re: maxdsiz 64 bit

Pete Randall — Fri, 10 May 2002 17:32:53 GMT

Andy,

From SAM help on configurable parameters:
Acceptable Values:
maxdsiz for 32-bit processors:

Minimum: 0x400000 (4 Mbytes)
Maximum: 0x7B03A000 (approx 2 Gbytes)
Default: 0x4000000 (64 Mbytes)

maxdsiz_64bit for 64-bit processors:

Minimum: 0x400000 (4 Mbytes)
Maximum: 4396972769279
Default: 0x4000000 (64 Mbytes)

From that, I would have to say no.

Pete

Re: maxdsiz 64 bit

Jeff Schussele — Fri, 10 May 2002 17:34:17 GMT

Hi Andrew,

Think they're pulling your leg.
The min value is 0x40000
Besides I wouldn't want any vendor or developer having "free rein" to set whatever size data segment they want. Heck they'd probably take it ALL.

Rgds,
Jeff

Re: maxdsiz 64 bit

Sanjay_6 — Fri, 10 May 2002 17:35:17 GMT

Hi Andrew,

I don't think "-1" is an acceptable value for maxdsiz_64bit,

http://docs.hp.com//hpux/onlinedocs/os/KCparam.MaxDsiz.html

Hope this helps.

Regds

Re: maxdsiz 64 bit

MANOJ SRIVASTAVA — Fri, 10 May 2002 17:48:38 GMT

Hi Andrew

No that paramter cannot have value as negative or -1 .

You may like to read this ;

http://docs.hp.com/hpux/onlinedocs/os/KCparam.MaxDsiz.html

Manoj Srivastava

Re: maxdsiz 64 bit

A. Clay Stephenson — Fri, 10 May 2002 17:59:19 GMT

You have received a state of the art stupid answer. You never want to defeat maxdsiz. This would allow a rogue process to grab all the resources on a box and bring it to its knees.
You certainly would not want a process to be able to allocate as much VIRTUAL memory as it could as this would instantly lead to huge amount of paging. As a sys admin, you need to decide how big that you will allow a single process to grow and still leave headroom for other processes. You then set maxdsiz (and its 64bit cousin) to these values.

Re: maxdsiz 64 bit

Andrew Luis Arruza — Fri, 10 May 2002 18:44:56 GMT

The replies have certainly backed up what my research found--and you provided me with additional 'ammunition.'
Thanks to all.