topic Re: Allocated memory in Operating System - HP-UX

Allocated memory

Ronelle van Niekerk — Mon, 02 Feb 2004 21:39:21 GMT

Is there a way to tell how much memory is allocated and how much is free?

Re: Allocated memory

Bill Hassell — Mon, 02 Feb 2004 21:56:49 GMT

HP-UX memory (and true for most Unix systems) is very complex. There is memory allocated to the kernel and to processes. But then there are shared resources such as the buffer cache and shared libraries. And programs can share memory with each other. HP-UX is also a virtual memory system so the amount of memory available to processes includes swap space. This means that more programs can be run than will fit into physical memory.

The only simple way is to run glance, a purchased product from HP that simplifies performance monitoring.

Re: Allocated memory

James Murtagh — Mon, 02 Feb 2004 21:59:32 GMT

Hi Ronelle,

The easy way to find the used memory is to find the free memory and subtract that from physical memory. You can find the free memory under the "free" column from the vmstat command. You can use various tools to find the physical memory, this command will work for 11.x ->

# echo phys_mem_pages/D|adb /stand/vmunix /dev/kmem

This is the number of 4k pages. You can also find it in the syslog, maybe dmesg will show it if its still in the buffer.

Cheers,

James.

Re: Allocated memory

Ronelle van Niekerk — Mon, 02 Feb 2004 22:10:27 GMT

Thanks guys,

Those are pretty much the answers I was expecting.
Was asked by a customer and just needed better wording to tell him that it will not be easy to find out.

-Ronelle