Hello, On Thu, Apr 23, 2020 at 07:13:43PM +0100, Mike Zanker via users wrote: Just checking: do you mean Ubuntu 18.04 (Bionic Beaver) to 20.04 (Focal Fossa)? If so then yes that's what I'm talking about; the kernel in 20.04 doesn't currrently boot at BitFolk because I think there is a (since fixed) bug in the LZ4 decompression code. If you mean Debian 9 (stretch) to Debian 10 (buster) then there are no issues that I am aware of, and I have done that procedure myself many times. You mention a clean install later on so maybe you just meant you're wanting to switch from Debian to Ubuntu. Cheers, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting

Hello, On Thu, Apr 23, 2020 at 05:15:03PM +0000, Andy Smith wrote: Okay, here's how to do this. If you've upgraded to Ubuntu 20.04 and now your kernel doesn't boot, this will get you a working 20.04 kernel but it will be uncompressed meaning it will take a fraction of a second longer to boot. You will also need to repeat the procedure every time there is a kernel update. https://tools.bitfolk.com/wiki/Ubuntu#No_support_for_LZ4-compressed_kernels… Hopefully that gets anyone who upgrades without seeing this warning out of a hole. Cheers, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting _______________________________________________ announce mailing list announce(a)lists.bitfolk.com https://lists.bitfolk.com/mailman/listinfo/announce

Hello, On Thu, Apr 23, 2020 at 05:15:03PM +0000, Andy Smith wrote: Some updates and some questions for customers about this. Firstly, there WAS a bug in Xen's LZ4 compression but that was only relevant for direct kernel load. That's when the guest's kernel exists as a file on the host's filesystem and is referenced in the config file for the guest. That's not how we boot guests at BitFolk, so that's not relevant; it isn't the source of the problem here. There's a detailed description of the boot process of a BitFolk guest here: https://tools.bitfolk.com/wiki/Booting The short version is: BitFolk has a grub binary that is compiled as a Xen PV guest kernel. This grub binary acts as your kernel, so it's the first thing a guest does when it's booted. It then looks for grub configuration in your block devices and if it finds it then it loads it. From your configuration it should find the correct actual Linux kernel and initramfs and chain load to them at which point booting proceeds normally. I don't yet fully understand how or why grub as a Xen PV kernel behaves differently to normal grub, but it seems like the Xen PV part of grub requires support for every kind of kernel compression, and no one has yet implemented LZ4 decompression for it. The "not a Xen kernel" error message comes from grub. My enquiries about this on the grub-devel mailing list have so far met with silence: https://lists.gnu.org/archive/html/grub-devel/2020-04/msg00198.html At the moment it doesn't look like anyone is interested in adding LZ4 kernel decompression to grub's Xen PV target. If you are capable of doing so (or know someone who is) but would need financial compensation to do so, please contact me directly; we may be able to work something out. Something that was pointed out to me is that when grub is compiled as a PVH guest it does handle LZ4-compressed kernels. I do want to move from Xen PV mode to Xen PVH mode but am not yet quite ready to do so. It does provide some reassurance though that there is a future where grub can continue to boot these things. A current workaround is to decompress the kernel. This is described here: https://tools.bitfolk.com/wiki/Ubuntu#Decompress_your_kernel Someone on the xen-users list pointed out that an apt hook can be used to automatically decompress kernels at kernel upgrade time: https://lists.xenproject.org/archives/html/xen-users/2020-05/msg00018.html The basic concept seems good though I do think their supplied script needs some security hardening (see my reply). My question to you is, if I made the BitFolk Xen Shell installer for Ubuntu 20.04 install such an apt hook so that it automatically decompressed LZ4 kernels, would that be an acceptable state to consider Ubuntu 20.04 officially supported at BitFolk? What would you be thinking the first time you did a kernel upgrade and saw apt call an extra script to decompress the kernel? At the moment Ubuntu 20.04 is not listed on the BitFolk web site as available, nor is there an installer for it in the Xen Shell, because of the need to decompress its kernel. It is only possible to install it by upgrade from an earlier release or by use of the Rescue VM - and then you need to take care of the kernel yourself. Put another way, is automating the decompression of LZ4 kernels at kernel upgrade time a good enough solution to allow Ubuntu 20.04 to be listed as available on the web site and in the Xen Shell? If the consensus is "no" then I think Ubuntu 20.04 will have to remain as not officially supported here until either there's a pvgrub that supports LZ4 kernels or BitFolk introduces PVH mode. Cheers, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting

On Thu, 7 May 2020, Andy Smith wrote: It sounds like a reasonable solution to me. However I have to admit the boot process is voodoo to me so I may not understand the downsides of such a solution. To be honest I doubt I'd notice. My current plan for finally moving away from 32 bit is to do a fresh 64 bit install of 20.04 and I've been waiting for 20.04 for about 9 months to execute this plan. So I'm keen to see 20.04 supported but having waited this long if I have to wait another 3 months it probably doesn't matter. If it ends up that 20.04 won't be supported for years (or ever) then I'll have to reconsider my migration plan. Andy

On Sun, 10 May 2020 11:14:47 -0400 (EDT) Andy Ransom <ARansom(a)gmail.com> wrote: you shouldn't have let Popey con you lot into moving away from the one true distro, Debian (lots of big grin smileys) John Lewis PS just converted my wife from Win7 to Debian Bullseye with Mate desktop, she loves it (more smileys)

On Sun, May 10, 2020 at 09:03:32PM +0000, Andy Smith wrote: ^^FIFTY!

On Thu, Apr 23, 2020 at 05:15:03PM +0000, Andy Smith wrote: Ubuntu 20.04 is now supported for new installs both as a new order or by self-install¹. This has required a small workaround be installed by us inside the guest, as detailed here: https://tools.bitfolk.com/wiki/Ubuntu#No_support_for_LZ4-compressed_kernels… Therefore if you intend to upgrade to 20.04 from 18.04 you will have to install that workaround yourself otherwise it won't boot afterwards. If you're looking at this because your VM now doesn't boot, no big drama: just boot the 18.04 kernel and install that workaround. Also please note that Ubuntu are only supporting 64-bit now so those of you on 32-bit will need a complete reinstall. Or you could chance a completely unsupported cross-grade. In theory 18.04 remains supported by Ubuntu until April 2023. Cheers, Andy ¹ https://tools.bitfolk.com/wiki/Using_the_self-serve_net_installer -- https://bitfolk.com/ -- No-nonsense VPS hosting _______________________________________________ announce mailing list announce(a)lists.bitfolk.com https://lists.bitfolk.com/mailman/listinfo/announce