Hello Reinoud

Thanks for the reply.

First off, it seems my problem with mdconfig on md1 is that I'm not
specifying the "control" device. The "control" device has a (minor) device
number of  "base device number"+0x10 (from the md.h comments) but I don't
see any file in /dev/ that hints at being this "control" device for md1.
Maybe I need to use mknod to create my own??

> > I want to set up /dev/md1 from user space at runtime. (I have two md's
> > defined in my kernel).
>
> so.. it may be empty? or would you like to load an image too like in md0?
> if not... then what's the problem with using mfs?

Well we have a diskless application, so space is an issue so I'd prefer to
exclude MFS from the kernel build and the mount_mfs utility (which I don't
seem to be able to find source code for).

Also, I cant seem to get mount_mfs to work as I expect it to. I dont quite
follow the man file explanation. When I do something like

mount_mfs -T mdroot swap /mnt

it always creates a 7911 x 1k "disk" no matter what I put for the -T option
(i.e. even if the disktab parameters do not indicate a "disk" of that size).

Now, the man page for mount_mfs says (I quote)
"If the -T flag is specified (see below), the special file is unused."

However, if I specify something other than the "swap" keyword for the
"special file" (eg /dev/md1c) then it does not actually mount anything, so
it seems despite the -T flag, the "special file" is in fact used???

> is it that is it stored in virtual memory, i.e. user space and not in
> kernel memory?

No, thats OK. What I'm trying to do with md1 also will allocate user space.

> well, thought about the line
>
> pseudo-device   md      1               # Ramdisk driver

Mine is definitely set to 2.

.
>
> > I could use mount_mfs I guess but then I'm forced to include the MFS
> > filesystem. Not necessarily a train smash but.....
>
> i have it installed as default... not that i use it; when looking at the
> code for creating the ramdiscimage for inclusion in a installkernel, i
> still don't get all it's doing... :-(
>
> is there some kind of howto ? or maybe some extra help in the manpages to
> be added (examples) ?
>
> > I get the idea (from the comments in md.h and md.c) that part of the
> > intention of "md" was to get away from the "MFS hack".
>
> i dont know.... for md0, ok... maybe thats a more clean way.
>

Well I personally understand better what the md stuff is doing, so I'm more
comfortable with that. mount_mfs is a bit mysterious for reasons I explained
earlier (I can't seem to get it to do what Iwant.)

Cheers
David