I have some old supermicro servers with over 16GB of ram in them which are still running 32bit version of linux with 2.6.x kernels and vmware on top of it.
I wonder if there is any advantage of upgrading the distro/kernel to a 64-bit Debian.
The only problem is that right now I cannot create 64 bit guest vms in vmware.
I would also like to know that, upgrading this system to 64bit have any performance advantage or maybe the more appropriate question would be that would it have any disadvantage?
Yes indeed it was a VS question and the only reason why I want to have 64 bit guests is btrfs, nothing else. I don't really have database, memcache or other vms which would take advantage of the 64 bit, also none of the VMs have more than 4 gigs of memory. The most I think has is around 2GB.
"32bit only rules in the 4GB or less RAM space" so many of my guests are just fine with being 32bit guests but my host OS which have 24GB ram and runs a 32bit kernel does some PAE tricks to access the memory over the 4GB.
So let me put it this way. If my main goal here is to have faster (or at least not slower) vms, would it be an advantage for the HOST os to be 64 bit? Would it access the memory area faster over 4GB than it does it right now?
Best Answer
If you're installing any OS in 2014 on modern hardware without 64-bit capabilities, you're making a bad design decision.
Even with the hardware RAM/CPU footprint you're describing for your VMware Workstation setup, it makes sense to utilize 64-bit versions of your operating system for forward compatibility, future-proofing and the very clear requirement you have for BtrFS 64-bit libraries.