Re: FC & MULTIPATH !? (any hope?)

[Brian Beattie <alchemy@us.ibm.com>]

On Mon, 2002-01-14 at 07:24, James Bottomley wrote:
> > > is there any hope of working combination of MULTIPATH with FC !?
> >
> > Yes. QLogic's newest 2200 HBA can do that. I don't know whether that is a
> > possible solution for your problem though.
> 
> To clarify: This solution is being pushed by IBM.  Unless you have a FASt 
> array, you may not get help making it work from either IBM or Qlogic.  You 
> also need the 5.x qlogic driver which you can download from the IBM website 
> (or from SuSE 7.3).
> 
> > At the moment I am using raid option multipath but it's one way
> > street, when one FC connection dies it successfully switches onto
> > another FC connection but when that second dies aswell, mount point is
> > in a limbo, no switching back to first FC connection.
> 
> I've tested the qlogic and it will switch to the secondary and back again on a 
> FASt 200 HA.
> 
> Although it was designed to work with the LSI Symplicity-4 AVT technology 
> (which is what IBM FASt's OEM), there's a high degree of probability that it 
> will also work with any array that the MD multipath driver also works for, so 
> good luck.
> 

I've been working with the multipath code.  Trying to add functionality
to it.  While I have not yet looked at this particular issue, if there
is interest I would be willing to see what can be done.  I do not think
it would be a big deal to add the functionality to reactivate a dead
path.  It should not be too hard to attempt to do so automatically.