Subject: Re: MEMORY_DISK_SERVER ?
To: David McConnell <davem@eastcoast.co.za>
From: Reinoud Zandijk <zandijk@cs.utwente.nl>
List: port-arm32
Date: 12/15/1999 11:05:09
Hello David,

I really can't on this, maybe it can be of some help,

On Tue, 14 Dec 1999, David McConnell wrote:
> I have /dev/md0 set up as a Kernel memory disk, i.e. MEMORY_DISK_SIZE is
> defined for the kernel build.
> 
> 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?

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

> However, when I do a mdconfig on md1, I get a "Device not configured". Now
> studying the source code mdconf.c and the md device driver (md.c md.h ) and
> md_hooks.c I can see why it returns that, but not how to get it to do
> differently??

well, thought about the line

pseudo-device   md      1               # Ramdisk driver

in your config file? As far as i know.. these numbers are the maximum
numbers of devices configured... so in this case just /dev/md0 and no
/dev/md1.

When commented out as by default in NetBSD/sparc, you get no md devices at
all... as for how to specify the size of md1... i really don't know...

> 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.

> Any comments ?

You got my 2 cents :-)

Cheers,

Reinoud