Re: [dm-devel] 2.6.10-rc1-udm1: multipath work in progress

[Lars Marowsky-Bree <lmb suse de>]

On 2004-11-08T17:01:01, christophe varoqui 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 suse de>

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