Re: geom, devfs

[Hiten Pandya <hmp@xxxxxxxxxxxxx>]

Ted Unangst wrote:

> On Fri, 12 Sep 2003, ibotty wrote:
>
>
> > do you/we plan to port geom[1] (or a similar) framework to DragonFly?
> > i came across this, when i thought about geom-gate, which looks very
> > interesting. 
>
>
> i'm currently implementing a "userland disk" for openbsd (inspired by 
> pawel's talk) which should be able to communicate with geom gate.  the 
> idea is basically the same, an ioctl interface passes read/write requests 
> to a userland daemon.  depending on the daemon attached, it could show up 
> as a networked device, or ccd, or something else entirely, maybe even 
> a gbde replacement.

	NetBSD had something interesting regarding disks; it isn't
	anything at the scale of GEOM:

		- cgd(4) driver

	Anyways, I have not looked at GEOM a lot, but once when it was
	all fucking up with the md(4) driver, because of a fault in the
	swapoff functionality in FreeBSD.

	From my point of view, what GEOM is doing, i.e. hierarching
	disk devices, should be done for the actual device framework;
	this way, things like GEOM can be easily made part of it.  It
	would allow us to put layers on top of each other.

	The Fluke dev. framework has some nice ideas which we might want
	to incorporate:

	http://www.cs.utah.edu/flux/papers/vanmaren-thesis-base.html

	Regards,

--
Hiten Pandya
hmp@xxxxxxxxxxxxx