[Mageia-dev] ANNOUNCE: The /usr move cometh! <---- Instructions

[Thierry Vignaud]

On 9 September 2012 20:42, Colin Guthrie <mageia at colin.guthr.ie> wrote:
>> Those cannot be done anymore.
>> Now updating rpm in order to be able to sole the unifiedsystemdir depends
>> pulls filesystem...
>> Classic egg & chicken issue...
>
> Yes, this has been a problem for a while now in Cauldron. But not many
> users are asking this question these days, so the likely path now is
> from mga2 -> cauldron which is probably where the effort should be focused.

BTW I tested live upgrade from FC17 to FC18.
It works smoothly if you don't have third party packages.
in FC there's no need for a special boot, everything is hanled by filesystem
package's pre/post scripts:

$ rpm -q --scripts filesystem -v
pretrans scriptlet (using <lua>):
--#
--# If we are running in pretrans in a fresh root, there is no /usr
and symlinks.
--# We cannot be sure, to be the very first rpm in the transaction list,
--# so, let's create the toplevel symlinks here and the directories
they point to.
--# When our rpm is unpacked by cpio, it will set all permissions and
modes later.
--#

if posix.stat("/usr") == nil then
    posix.mkdir("/usr")
end

for i,dir in ipairs({"/lib", "/lib64", "/sbin", "/bin"}) do
    if posix.stat("/usr"..dir) == nil then
        posix.mkdir("/usr"..dir)
        if posix.stat(dir, "mode") == nil then
            posix.symlink("usr"..dir, dir)
        end
    end
end

return 0
postinstall scriptlet (using <lua>):
posix.symlink("../run", "/var/run")
posix.symlink("../run/lock", "/var/lock")