Antw: [EXT] Re: Support for unmerged-usr systems will be REMOVED in the second half of 2023

["Ulrich Windl" <Ulrich.Windl@xxxxxxxxxxxxxxxxxxxx>]

>>> Luca Boccassi <luca.boccassi@xxxxxxxxx> schrieb am 05.11.2022 um 12:32 in
Nachricht
<CAMw=ZnSzha8YDZGNTRHTFpLuuL6pHykrNnPd1a7uyE7riMfkbA@xxxxxxxxxxxxxx>:
> On Sat, 5 Nov 2022, 10:53 TJ, <systemd@xxxxxx> wrote:
> 
>> On 05/11/2022 10:36, Mantas Mikulėnas wrote:
>> > On Sat, Nov 5, 2022 at 12:06 PM TJ <systemd@xxxxxx> wrote:
>> >
>> >> Just seen this announcement in the v252 changelog:
>> >>
>> >> "We intend to remove support for split-usr (/usr mounted separately
>> >> during boot) ..."
>> >>
>> >> How does this align with support for separate /usr/ with dm-verity ?
>> >>
>> >> For example, this will affect nspawn. See "man 1 systemd-nspawn" and
>> >> "--root-hash=" where in respect of /usr/ it says:
>> >>
>> >> "Note that this configures the root hash for the root file system. Disk
>> >> images may also contain separate file systems for the /usr/ hierarchy,
>> >> which may be Verity protected as well. The root hash for this
protection
>> >> may be configured via the "user.verity.usrhash" extended file attribute
>> >> or via a .usrhash file adjacent to the disk image, following the same
>> >> format and logic as for the root hash for the root file system
described
>> >> here."
>> >>
>> >
>> > /usr can remain on a separate partition as long as it's mounted *by the
>> > initrd* (the same way initrd currently mounts your rootfs), so that by
>> the
>> > time systemd starts it already has the full filesystem.
>>
>> How does this work when systemd is used inside the initrd, as
>> "recommended" / discussed at, for example "Using systemd inside an initrd"
>> :
>>
>> https://systemd.io/INITRD_INTERFACE/ 
>>
>> > What's finally being removed is support for having the rootfs itself
>> mount
>> > /usr halfway through, which requires many things that normally are on
>> > /usr/lib to be split between it and /lib instead (such as on Debian).
>> >
>> > Using the initrd to mount /usr isn't new.
>> > <
>> 
>
https://web.archive.org/web/20150906203654if_/https://www.gentoo.org/support/

> news-items/2013-09-27-initramfs-required.html
>> >
>> >
>>
>> Does it also affect the command-line options "mount.usr=,
>> mount.usrfstype=, mount.usrflags=, usrhash=, systemd.verity_usr_data=,
>> systemd.verity_usr_hash=, systemd.verity_usr_options=" as per "man 7
>> kernel-command-line" ?
>>
> 
> No, that is unrelated. This is about the ancient notion (that no initrd
> tools support anymore) that you can boot userspace with /bin /lib /sbin and
> no /usr, with the latter being set up late at boot. This is what is no
> longer going to be supported.


..by systemd developers

And so the Linux OS world must change...

> 
>>