[bitfolk] Linux ended 32-bit PV guest support with v5.9, which means no Debian 11 (bullseye)

Hi, Yesterday evening and again this morning we've had two customers try to upgrade their 32-bit Debian 10 VMs to Debian 11 and end up with something that doesn't boot. This is because the Linux kernel stopped supporting 32-bit Xen PV domains at version 5.9. The quick workaround for those on Debian 10: xen shell> virtmode pvh xen shell> boot We have talked a lot about this over on the "users" list over the years, and for a while now the default at BitFolk has been 64-bit, PVH mode guests, but we can't switch existing customers over to PVH mode because it requires at least kernel version 3.19 and we don't know what kernels you're running. So existing customers have been left to switch on their own. Switching to PVH mode will for now allow you to continue to run 32-bit VMs. However, aside from this, 32-bit Linux has been in decline for some time and it's know to be less performant and less secure than 64-bit. So the time has already passed where you should be planning your switch to 64-bit. == Just switching your kernel == Most of the advantage is to be gained by just switching the kernel, so those running Debian could do that as Debian has good support for this. 1. Upgrade to Debian 10 (buster) 2. Follow these instructions only up to and including the "Install a kernel that supports both architectures in userland" step. 3. Connect to your Xen Shell 4. Shut down, boot, select the new amd64 kernel xen shell> shutdown xen shell> boot If for any reason this does not work, just boot again and select your previous i686 kernel again. We suggest doing this in the Xen Shell so you can interact with the boot process because the new amd64 kernel may not be listed first in your bootloader. 5. Once satisfied that your amd64 kernel works you can remove the i686 kernel packages. Debian will take care of providing you with amd64 kernel updates in future. If you haven't already done so you should consider switching to PVH mode now as well. We do not recommend trying to fully cross-grade your operating system to 64-bit unless you are an expert. == Reinstall == You can do a reinstall in place yourself: https://tools.bitfolk.com/wiki/Using_the_self-serve_net_installer Don't forget to first switch your architecture to 64-bit and your virtmode to PVH: xen shelll> arch x86_64 xen shell> virtmode pvh as these are the modern defaults. We can also offer a new account free for two weeks for you to install into and move your things over. https://tools.bitfolk.com/wiki/Migrating_to_a_new_VPS == PVH mode? == Which virtualisation mode you use is rather something we don't expect customers to have to worry too much about, so new customers have been in PVH mode for some time and haven't had to think about it, but existing customers will need to make the change at some point. Anyone with a kernel that's 4.19 or newer should be able to switch to it. Here's more info: https://tools.bitfolk.com/wiki/PVH Cheers, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting _______________________________________________ announce mailing list announce(a)lists.bitfolk.com https://lists.bitfolk.com/mailman/listinfo/announce