[systemd-devel] /usr on separate file system

[Tomasz Torcz]

On Thu, Mar 03, 2011 at 06:45:21PM +0100, Lennart Poettering wrote:
> On Thu, 03.03.11 17:58, Tollef Fog Heen (tfheen at err.no) wrote:
> 
> > 
> > ]] Lennart Poettering 
> > 
> > | > To boot a system, enough must be present on the root partition to
> > | > mount other filesystems. This includes utilities, configuration,
> > | > boot loader information, and other essential start-up data. /usr,
> > | > /opt, and /var are designed such that they may be located on other
> > | > partitions or filesystems.
> > | 
> > | Well, turns out no distro really follows the spec here, do they?
> > 
> > Given the number of Debian people I see running with separate /usr, I
> > believe it works just fine there and while it's a supported
> > configuration I'll patch the warning out of the Debian systemd packages,
> > at least.
> 
> Well, it's of course up to you guys what you do there.
> 
> But it's a promise you are making there that you cannot keep. If you
> want to support /usr on a separate partition then you'd need to do all
> the work and move the PCI and USB databases to /, move libatasmart,
> fix udisks, fix D-Bus and so on.
> The fact that most these things fail relatively gracefully should not
> mislead you to believe that everything worked fine. Things still fail,
> just not in a big gigantic atomic explosion scenario.

  I don't get it. What during the boot (before /usr is mounted) require pci.db,
usb ids, why udisks would be started?  I understand that full desktop session
need access to those, but we are talking about short window before starting
system and mounting /usr.  What will break?  Are the some udev rules needing
mapping between PCI ID and a name?  Anything else?

  (BTW, “yum remove libatasmart” suggest removal of udisks, nautilus, gvfs,
evolution and some GNOME parts.  Nothing related to boot).

-- 
Tomasz Torcz                                                       72->|   80->|
xmpp: zdzichubg at chrome.pl                                          72->|   80->|