On Sun, Dec 02, 2018 at 11:31:13PM +0100, Marco d'Itri wrote: > On Dec 02, Wouter Verhelst <wou...@debian.org> wrote:> > > One thing that has not been answered yet in this discussion (and if the > > TC is to make a decision about it, I think it should be) is "why are we > > doing this". That is, what is the problem that usrmerge is meant to > > solve, and how does it attempt to solve it? As far as I know, the reason > > usrmerge exists is so that no files will be installed in /bin anymore; > > but that seems like an XY problem. > https://lists.debian.org/20181121140542.ga31...@espresso.pseudorandom.co.uk
That post is too long-winded and touches so many unrelated issues that it's difficult to respond to it. Could you please give us a terse list of claimed benefits? Without a clear claim, it's too easy to both do or be accused of doing a straw-man. By my reading, most of that post either falls into the XY problem or explains how merged-usr fixes problems caused by merged-usr itself. That leaves only one concrete claim: * that merged-usr makes it easier to have a part of the system immutable (be it for recovery purposes or for sharing) My response to that claim is: there's a long list of techniques that can be used for such an effect without sweeping distribution-wide changes. Heck, not even a couple of hours ago I restored from a snapshot multiple times in order to troubleshoot a broken udev problem. Here's your "This means you always have a known-working filesystem to fall back on (if the most recently updated filesystem doesn't boot, use the other one)". Or, container sharing: works fine for me without merged-usr either. Thus, in order to make this claim stick, you need to not only list its benefits but also explain how it's better than other approaches: filesystem-based (btrfs, ZFS, XFS), vfs-based (various overlays), lvm-based/-like, block-device based, multiple mounts, etc. And, many of those can do CoW which is so much better than immutability. (Please explain if I understood you wrong.) Meow! -- ⢀⣴⠾⠻⢶⣦⠀ ⣾⠁⢠⠒⠀⣿⡁ Ivan was a wordly man: born in St. Petersburg, raised in ⢿⡄⠘⠷⠚⠋⠀ Petrograd, lived most of his life in Leningrad, then returned ⠈⠳⣄⠀⠀⠀⠀ to the city of his birth to die.