raid framework from OpenBSD

Joao Barros joao.barros at
Mon Sep 19 08:11:29 PDT 2005

On 9/16/05, Scott Long <scottl at> wrote:
> Joao Barros wrote:
> > On 9/14/05, Scott Long <scottl at> wrote:
> >
> >>Massimo wrote:
> >>
> >>>I would like to know what do you think about new OpenBSD raid framework
> >>>management.
> >>>
> >>>
> >>>Doesn't it seems good stuff which is good for consideration?
> >>>
> >>>Regards.
> >>
> >>Creating a unified management tool for multiple RAID architectures has
> >>been a Holy Grail for at least 10 years, if not longer.  It's
> >>deceptively hard, though.  While it sounds straight-forward and is
> >>relatively easy to do for 1 or 2 architectures, the vast differences in
> >>how different architectures work makes it quickly turn into a huge mess.
> >>This is especially true when it comes to topology discovery and
> >>management and asynchronous event notification.  Often times the only
> >>course is to degrade to a very simple, lowest common denominator
> >>interface, which then starts to limit the usefulness of the tool.  I've
> >>been involved in several professional projects in exactly this area, and
> >>it simply is very, very hard to do well. The OpenBSD work looks
> >>interesting, but unless they can demostrate useful operation on more
> >>than 1 or 2 architectures, it's not terribly impressive.  That's not to
> >>say that it can't be done and be a success, but the amount of required
> >>effort should not be underestimated. It's relatively easy to come up
> >>with a framework and implement one architecture module in it, then tell
> >>everyone else to simply add more modules.
> >>
> >>Also, it's not clear from the email whether the tool has to be manually
> >>told to rescan and look for changes in the state of the array (not just
> >>SES/SAFTE changes of the component drives).  Displaying status on demand
> >>is fine, but what admin sits in front of their terminal and refreshes
> >>their monitoring apps every 5 seconds?  The key is to have a an event
> >>notification pipeline that can collect events in near real time, filter
> >>them in a configurable way, and send out email/pager alerts when
> >>appropriate.  Also, what does this mean for a datacenter full of
> >>machines that need to be monitored?  Does a remote terminal session need
> >>to be opened on each one in order for monitoring to work?
> >>
> >>But, even if this particular work degrades into only being a tool for
> >>AMI (I assume they mean MegaRAID) controllers, it's still useful and I
> >>give them credit for doing it.
> >
> >
> > Having an amr I'm most interested in this, as I guess more people are.
> > Given that there is "customer" interest, my question is: is there
> > interest from you in this, having it imported to FreeBSD?
> > I've looked at the code and I wouldn't mind starting to work on this.
> >
> > --
> > Joao Barros
> Give it a try if you're interested.
> Scott

I'v talked to marco at openbsd and he seemed very open to the idea and
available to assist me :)

The machine I have the ami installed is rather slow, a PIII 733MHz and
today at work I reserved a Compaq DL380 with a 3.0GHz Xeon and a ciss(
I think) which according to the controller's documentation already has
bio support, so I'll be able to test both controllers. I have access
to Dell (amr mostly), IBM (isp), and Compaq machines so I can try and
add support for more controllers :)

Joao Barros

More information about the freebsd-current mailing list