create 64bit templates

I'll look into this, as a few customers have requested it.

32-bit KVM instances should run fine on a 64-bit host though (but of course with limits on the amount of RAM they can use).

Sure, most programs contain a huge amount of memory pointers, and on a 32 bit system those will each take up 4 bytes. On a 64 bit system they instead take up twice as much; 8 bytes. It will therefore take a few percent more RAM to run 64-bit.

That small problem aside, it's pretty silly to create 32-bit guest machines these days. It's slow and limiting.

By running a 64-bit kernel, your machine will be able to use native 64-bit math, which on average means 15-25% faster code execution for math-intensive work (with SSL/HTTPS calculations being a major one that benefits, as OpenSSL runs ~2x as fast under 64-bit), which is what really matters. I.e. a 64-bit multiply could be done in a single operation (rather than let's say 10 smaller 32-bit operations that have to split the work into smaller chunks, process them independently and re-join them later).

Moreover, if you start out with a 32-bit guest machine, there is no way to ever add more RAM to it since you cannot convert it to 64-bit without a re-install.

So, it just makes a lot of sense to have 64-bit images available across the board for all VM types. Even if you never go above 4 GB of RAM, it's great to be able to get a lot more work done per clock cycle, which translates to more concurrent users that the server can handle, especially when it comes to the 2x faster HTTPS/SSL traffic.

I don't think anyone should be making 32-bit servers these days. We're leaving that world behind.

+1 from me.

(Happily on the CentOS 64-bit Xen images here. Thanks a lot for those.)

Let me +1 for this as well - 64-bit centos kvm images would be great, especially since I continue to have various issues creating my own - even the latest cloudmin release still seems to not be able to boot correctly from DVD when the system is built with VirtIO enabled. (Yes, I've read the workarounds and am pllugging away at that, but it'd be great if we either had a prebult 64-bit template system OR the building an empty system just worked right).

FYI, three 64-bit images for KVM are now available for all users - CentOS 6.4, Debian Squeeze and Ubuntu 12.04.

Automatically closed -- issue fixed for 2 weeks with no activity.