[dm-devel] 2.6.10-rc1-udm1: multipath work in progress
Lars Marowsky-Bree
lmb at suse.de
Mon Nov 8 16:55:14 UTC 2004
On 2004-11-08T17:01:01, christophe.varoqui at free.fr wrote:
> > Yes, that's why I asked how you'd want to implement it in the
> > multipath-tools. /sbin/multipath must find out somehow which PG to
> > activate first, right?
> >
> Right : it already does.
No. The mechanism you describe allows the path-prioritizer to influence
the order of the priority groups, yes.
But the in-kernel scheme discussed here allows a PG to be active w/o
being the one in the front.
> I guess you can alter the pg priorities the way anyone can imagine
> based on that framework. With the current kernel driver, PG are fed in
> params strings in top-down summed-path-priority order.
>
> Feeding those priority numbers directly into the params strings and
> keep the PG statically ordered shouldn't be too invasive a change.
That's the right direction, but not all the way, I think. The priority
of the group is not the same thing as whether it's active or not.
I think an additional call-out to query for the active or bypassed
status for the PG is needed.
Sincerely,
Lars Marowsky-Brée <lmb at suse.de>
--
High Availability & Clustering
SUSE Labs, Research and Development
SUSE LINUX Products GmbH - A Novell Business
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