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

[Bjorn Ramqvist]

Gregory Leblanc 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 should look into that right now.

> > Right now I'm in the middle of investigating a SMB-fileserver and I want
> > to avoid Windoze as much as possible, thinking Samba.
> > The problem is, that our storage arrays (Compaq MA8000) runs with
> > multibus failover. That is, four active paths to the same storageset on
> > the controller. Now, this is perfectly working from inside Tru64 5.x and
> > OpenVMS, and Windoze NT/2k with "Secure Path" software for a massive
> > amount of $$$.
> 
> Sounds like you want a nice Alpha running OpenVMS to me.  Samba is
> supposed to be nice on that platform, though I've never gotten IP
> working on my OpenVMS machine.

Well, right now I have a new shiny TruCluster with two Alpha ES45. I'm
running Samba (with TruCluster patch applied) on it, and it seems to
work fine. These two babies are going to be dedicated for ORACLE, and
nothing else. We have somewhere near 60GB database that servers near
1000 users, so PeeCee-fileserving on those would be... Hmm, tricky. :-)
We're running an OpenVMS cluster with about 100+ nodes for CAE/CAD
applications, so we're familiar with VMS for 10+ years. It's nice, but
it's not that highperforming when it comes to fileserving, from what
we've seen. Ofcourse, it's a highly solid performing platform, but it
doesn't cut it for our needs.

There's not a snowball-chance in hell that I can justify the cost for a
$25,000-$50,000 machine for serving PeeCee-users, when they expect a
PeeCee serving PeeCees. I might get away with it through the use of
Linux, but that's probably the limit. (x86)
Heck, right now (the PeeCee+Windoze alternative) the cost is up
somewhere in the $6,000 for the machines, and another $12,000 for the
disks (about 700 GB). That does not include the Array controllers, since
we're re-using the SAN Arrays for this task.

> > Right now I want to keep the budget tight and investigate the
> > alternative -> Linux w/ Samba & FC-RAID, redundant.
> > So far, no good. Anyone else has a clue?
> 
> There's support, and there are tools called 'mdadm' that deal with some
> of what needs to be done.
> http://www.cse.unsw.edu.au/~neilb/source/mdadm/  If you've got specific
> questions, I can try to answer them, but hopefully that will at least
> get you pointed in the right direction.

I'll look into that as soon as possible. Thanks.

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