[Pkg-xen-devel] Bug#452721: #452721 is kind of important

[Elliott Mitchell]

found 452721 4.8.5+shim4.10.2+xsa282-1+deb9u11
quit

I'm inclined to suggest #452721 is actually a bit more than merely
wishlist.  The ordering of domain start/restore/stop/save can be
extremely important.  The current behavior of the xendomains init script
is rather simplistic.

I would argue for the use of tagging along the lines of what was
standardized for init scripts.  Domains acting as LDAP/NIS/syslog would
need to start before fileserver domains.  Mailserver domains would start
after nearly all other domains had start.  These would likely be stopped
in /almost/ the reverse order (there could be reasons for
stopping/suspending them in an unrelated order).

Rather more interestingly, one might desire some domains to start in
parallel with some services started by init scripts; yet others to start
near the end of the init process.  Perhaps modify /etc/init.d/xendomains
to be called multiple times during system startup/shutdown?  Maybe there
could be links /etc/rc2.d/S02xendomains:early,
/etc/rc2.d/S03xendomains:middle, and /etc/rc2.d/X04xendomains:late which
start "early", "middle", and "late" domains?

Pretty much it really needs to be redone from the ground up.



Related, but perhaps a distinct issue is what happens when one runs
`/etc/init.d/xendomains reload`.  The current behavior is to pause/stop
all domains and then resume/start all domains.  One use for this is for
when qemu-system-i386 gets security updates.  In such case the desired
behavior is to stop and then start each domain (which results in shorter
downtimes for each domain, even though the whole process takes just as
long).


-- 
(\___(\___(\______          --=> 8-) EHM <=--          ______/)___/)___/)
 \BS (    |         ehem+sigmsg at m5p.com  PGP 87145445         |    )   /
  \_CS\   |  _____  -O #include <stddisclaimer.h> O-   _____  |   /  _/
8A19\___\_|_/58D2 7E3D DDF4 7BA6 <-PGP-> 41D1 B375 37D0 8714\_|_/___/5445