[dm-devel] [PATCH 2/4] libmultipath: fix priorities in parse_vpd_pg83

[Benjamin Marzinski]

On Mon, Mar 29, 2021 at 07:08:14PM +0000, Martin Wilck wrote:
> On Mon, 2021-03-29 at 13:20 -0500, Benjamin Marzinski wrote:
> > > 
> > > multipathd could figure out the system configuration from the (non)
> > > availability of certain properties, and use an appropriate fallback
> > > logic for either case.
> > 
> > That seems like reasonable first step, although one that won't help
> > SID,
> > since it can't rely on getting the wwid from udev. 
> 
> Can you conceive of a different approach that would be better for SID?
> I'd like to hear about it.

I assume that we will continue to have a fallback function to get the
wwid, that will get the proper wwid. As long as you are O.k. with
multipath autodetecting if SID is running, it can just continue to use
the fallback method, so this should be fine.

> >  This actually brings
> > up a different point I have. Is your main objection to adding more
> > config options that it is complicating the code, or confusing the
> > users?
> 
> Both, with emphasis on the latter. I'm quite positive that we have too
> many options already. That doesn't mean I would generally oppose new
> options if they make sense. We should rather try to get rid of some new
> ones that nobody uses any more.
> 
> > Because multipath wouldn't need to add any configuration options to
> > be
> > easily usable with SID (the current workaround, setting uid_attribute
> > to
> > "", is pretty non-obvious to users) if it could just check if sid was
> > running, and key off that.  However this adds even more code
> > complexity
> > than simply checking a config option. I don't know how you would feel
> > about accepting a patch that does this, when SID is production ready.
> 
> I could live well with this autodetection. I think it would be better
> than doing the same thing with a configuration options.
> 
> Regards,
> Martin
> 
> 
> -- 
> Dr. Martin Wilck <mwilck at suse.com>, Tel. +49 (0)911 74053 2107
> SUSE Software Solutions Germany GmbH
> HRB 36809, AG Nürnberg GF: Felix Imendörffer
>