maximum amount of memory on HP9000 & HP-UX 10.20

[LEJARRE Patrick]

What is the maximum amount of memory a process can use on HP9000 workstations on which HP-UX 10.20 has been installed.
How to tune the kernel to reach this maximum value ?
Environment: 3D CAD applications

[Printaporn_1]

Hi,

Please consider maxssiz, maxtsiz and maxdsiz
you can goto sam -> kernel configuration -> configurable parameter

select the parameter , press F1 you can see
minimum , maximun and default for that parameter.

thanks

[John Bolene · Accepted solution]

First, this depends on your hardware and its limits.
The C110, the machine I am the most familiar with, has a limit of 512M.
Second, I am not sure if 10.20 has a limit on memory, it should be at least 2 Gig.
Most of the newer servers require UX 11.x which has a much higher limit.

[Bill McNAMARA_1]

Johns right.
The superdome 64 way server will allow you 256GB with 512MB dimms.. later upgradeable to 1GB dimms.

Really depends on your slot numbers and dimm sizes not the OS... well 32Bit versus 64bit will make a difference, but hpux 11 based 64bit oses are all you will find on the likes of the superdome and V class.

Later,
Bill

[John Bolene]

I forgot to reply on kernel tuning.
You most likely do not have to do anything.
The kernel is dynamic and will use what memory it needs, the rest of it is used for buffering I/O.
You only have to change kernel parms if something is aborting saying it can't get more memory.
Normally the programmers that wrote the application you run will have already determined if any parms need to change and will include this information in the install manual. If these are your own company's programmers, well then you have to be a bit more proactive and look at what is happening on the server when it is being used.

If this does not answer the question, I need a bit more information on where you need more help.

[LEJARRE Patrick]

Apparently, the maximum value a process
can use in HP-UX 10.20 is 2 GB.
Is it true ?

We have a process that needs much more
than 2GB memory ( 3D CAD application ).
It aborts regularly displaying the
message:
Serious error: Out of virtual memory.
Starting recovery attempt.

We set kernel parameters as follow:
maxdsiz 0x7b03a000 ( which is the max
value authorized by sam -> 2 063 835
136 bytes)
maxswapchuncks = 1548

The swap space is 2 x 1,5 GB.
Installed RAM: 1,5 GB

The problem is that our process aborts
before reaching the ( RAM + SWAP) space.

In our opinion, the system is correctly
configured. Is there any other
possibility to better tune the kernel ?

[Edward Sedgemore]

Take a look at the following earlier question and answer on how to allow a process under 10.20 to use 3 GB of RAM, which patches you will need and ACE bundle loaded etc..

http://forums.itrc.hp.com/cm/QuestionAnswer/1,1150,0x56f46c96588ad4118fef0090279cd0f9,00.html

[LEJARRE Patrick]

Hi Edward,
This related link concerns only HP-UX 11.x.
Is it true ?

[Edward Sedgemore]

Ops, indeed that was for 11.0 Sorry.

The max memory amount of shared memory a process can use on 10.20 is 2.75 Gb. See the following links;

http://www.dutchworks.nl/htbin/hpsysadmin?h=3&dn=14730&q=maximum%20memory%2010.20&fh

http://www.dutchworks.nl/htbin/hpsysadmin?h=3&dn=22919&q=maximum%20memory%2010.20&fh