Restricting available physical memory in Linux

marcdbl · 11-06-2009, 04:36 AM

I am doing some application testing, using CentOS 5 running on x64 with 32GB of physical memory.
I want to see how the application behaves when only 8GB of physical memory is present in the server. Is there a way I can artificially restrict the physical memory to a lower amount such as this?

I can't remove DIMMs from the machine as it's in a remote datacentre.

Windows makes it easy using the /maxmem boot options, but I can't find any reference to such a trick in Linux....

Thanks.

cantab · 11-06-2009, 08:15 AM

mem=MEMEORY_SIZE. Put it in the grub configuration line that starts 'kernel'.

MensaWater · 11-06-2009, 08:34 AM

You could always install the Xen kernel and setup a virtual machine that has the characteristics you want.

marcdbl · 11-06-2009, 09:29 AM

Quote:

Originally Posted by cantab

mem=MEMEORY_SIZE. Put it in the grub configuration line that starts 'kernel'.

Thanks Cantab, that looks just the job.

(Unfortunately I need to be testing native performance so Xen is no-go in this case).