[geeks] [SUMMARY] OT Q: Multiple paths to storage in Linux

[Bjorn Ramqvist]

Bjorn Ramqvist wrote:
> 
> > > From what I can see, Linux doesn't support multiple paths to Storage?
> >
> > You're looking in the wrong place.  It's called "multi-path" support.  I
> > think it's in with the software RAID options (though it's not software
> > RAID)
> 
> I think I'm getting somewhere close to what I'm seeking:
> http://open-projects.linuxcare.com/t3/
> 
> However, this seems to be developed for Sun T3 arrays only.

Damn. Now I'm replying to myself. :-)

I think I've narrowed it down to one single point of interest now ->
Linux MD.
The MD driver in newer (2.4.10 and forward) kernels has a feature called
"multipath", which in a way makes the MD daemon be responsible for
failing over to other paths to the same storage. Nice.

My storageset would most likely show up as four independent devices with
exactly the same geometries/capabilites when the kernel starts, hda,
hdb, hdc and hdd. Whenever MD decides to show up, compiled-in with
"multipath" option, it takes care of these "four independent disks" and
place them under MD control as one single unit.

I still have yet to test this in reality, but atleast I know what to do
when that time comes.


Thanks to Gregory Leblanc for the tip.

-- 
Vdnliga hdlsningar/Best Regards
Bjvrn Ramqvist, Hdgglunds Vehicle AB