ASL kenel for i386 can't hadle more them 2.5GB RAM?

TheEniGMa · Unread post by **TheEniGMa** » Fri Aug 15, 2008 6:12 am

Hello.

We are testing the ASL2 kernel (kernel-2.6.25.4) on a new Quad-core XEON-box with 6GB of DDR RAM. Centos 5.2 32bit i386-version being used.

When we are running the ASL kernel (or the standard Centos linux kenel) we only get 2.5GB of memory recognized by the system. We then tried to install the kenel-PAE (from CentOS) witch booted up with the full 6GB of memory. Is there any way we can use the ASL kernel on this system without losing the RAM?

However, we are basically only using standard CentOS standard rpms and PLESK rpms, both available in 64-bit, so perhaps the easiest (and best) way it to simply install the 64bit version of CentOS?!

breun · Unread post by **breun** » Fri Aug 15, 2008 6:46 am

Yes, definitely go with 64-bit if you have more than 4 GB RAM. 64-bit will perform better than the PAE kernel.

Unread post by **scott** » Fri Aug 15, 2008 9:37 am

This is because a 32-bit systems can only really address 4G of memory (this is the max size of a 32-bit int). If you're only seeing 2.5G sounds like you've got some sysctl settings out of whack on the system. You should be able to see 3.9G + kernel overhead.

breun · Unread post by **breun** » Fri Aug 15, 2008 9:58 am

I have also heard of systems that had only 3.25 or 3.5 GB available with a 32-bit kernel. Anyway, go 64-bit if you have 6 GB of RAM.

TheEniGMa · Unread post by **TheEniGMa** » Fri Aug 15, 2008 10:53 am

I will simply go ahead and install 64-bit. Sounds like the best solution without any real disadvantages (I rather see advantages...)

Thanks for the fast replies Scott and Breun!