I just confirmed in slicehost chat, that while the kernel itself will still be 64 bit and use a little bit more ram then a 32 bit kernel, all the other programs will be 32bit and in theory run with less memory consumption.
These 32-bit machines use too much memory. I only need a 31-bit address space! Can you guys please drop everything to support my micro-optimization needs?
I agree ... it's a major pain on EC2 to have separate images that are only used for the smallest instance sizes. While 32 bit vs 64 bit pointers do save RAM on these small machines, I think you make a good point in an amusing way, and you shouldn't be downvoted for that.
I am mostly commenting on the comments on the blog. "You guys have excellent customer service, so maybe I'll switch back after you make some obscure change for me that I could make myself, but am too lazy to."
If you want a 32bit userland, just make a directory, debootstrap the i386 userland there, and schroot to it. It's a 30 second operation.
"Unfortunately, the RPM based distro's such as CentOS and Fedora do not have 32-bit ELF support so we are, at this stage, unable to offer equivalent images for those particular distros."
Wow. I didn't know Slicehost was on crack.
Can somebody explain to me WTF they mean that RPM-based distros don't have support for 32-bit ELF files? CentOS and Fedora have been using 32-bit ELF binaries forever.
I suspect what they mean is that Fedora doesn't support running at 64-bit kernel with a 32-bit userland. The problem starts with the initramfs, and I suppose slicehost is not in the business of modifying to underlying OS all that much.
Modern CentOS distros ship both 32-bit and 64-bit binaries (including 64-bit kernels). All they should need to do is kick a 64-bit image and remove the 64-bit binaries, and change your yum repo to a 32-bit one only. If the initrd was an issue they'd just switch to the other arch's initrd or rebuild kickstart-images with whatever support they need. This is pretty easy stuff.
Does this mean memory consumption will be similar to that of 64-bit images, since the kernels are the same?
It seems the same amount of memory on Slicehost slices doesn't go quite as far as that on 32-bit VPSes.