Hi Alex, Am 15.09.2016 um 13:47 schrieb Alexander Graf:
[...] because we have people who have Leap 42.1 and current Tumbleweed installed, we can’t just switch from 64k to 4k PAGE_SIZE, because our friend btrfs embeds the page size into its on-disk format and can only read it when they’re identical. So switching would break existing btrfs installations.
There hasn’t been any well working solution to make btrfs more compatible, we don’t really want 42.2 to diverge from its origins and 4k gets us running on smaller systems which are starting to pop up more and more in the 64bit world. Given all that, is anyone seriously opposed to switching everything to 4k?
I am opposed for Tumbleweed. And I already expressed deep concerns about 42.2 despite not affected myself: In particular I find it very troubling that some people including Ludwig himself are now in hindsight degrading our stable 42.1 release to some experimental thing that supposedly no one has installed or cares about - then we don't need a 42.2 release either and could focus our efforts on Tumbleweed instead!
We could have a patch like the one below in the kernel pre-install script, preventing people from breaking their systems, add notes on the wiki, maybe ask SoftIron to send emails to people who bought systems with Tumbleweed/42.1 preinstalled and then close that horrible chapter forever.
Note that your patch does not address the 42.2 installer, whose kernel and initrd to not get installed by rpm. I would be okay for Tumbleweed iff instead of that horrible blocker patch we could get a patch for, e.g., dracut to convert the volume from 64k to 4k on boot if necessary, keeping zypper dup working that way. Is there no FUSE implementation or some btrfs(8) subcommand to change the blocksize without having to mount it in the kernel? Also, didn't you suggest using a KMP with patched btrfs module, to abstract the page size? I thought that was your designated solution for at least Tumbleweed. For Tumbleweed I think it's reasonable to expect people to do a zypper dup instead of .iso upgrade. (No, there are not JeOS images for every platform, and even if there were, not everyone wants to loose all their data and the currently well working upgrade path.) How does GRUB2 deal with btrfs page size? Does it need to get reinstalled after switching kernel page size or does it use a "better" driver implementation than the kernel? Any other userspace packages that may require a rebuild if changed? In general, please keep in mind that with an Open Source project like this you never have full information about your users. Not every user is subscribed to this list. Not every user subscribed will be reading questions timely, in particular given that 42.2 Beta 2 checkin is today already. Which was my main concern, after this topic already missing Beta 1. Regards, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) -- To unsubscribe, e-mail: opensuse-arm+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-arm+owner@opensuse.org