Re: RAID with Disk ][

[Greg Buchner <null@none.invalid>]

In article <dog_cow-1273538011@macgui.com>,
 dog_cow@macgui.com (D Finnigan) wrote:

> Imagine this: One controller card, 2 Disk ][ units, and ProDOS device
> drivers to handle the following types of RAID configurations. I think that
> it can be done.
> 
> Mirroring- write data to Drive 1, then write it to Drive 2. Reads could
> choose either drive 1 or 2.
> 
> Concatenation- Drive 1 and Drive 2 combine to yield a whopping 280KB
> (without needing to flip). The device driver would need to scan both
> catalogs, or make a combined in-memory catalog for a speed-up.
> 
> Striping - Can this be done in any meaningful way??? I don't think so. Not
> with the given hardware, I don't suppose.
> 
> Out of the possibilities, I think that concatenation would be most useful.
> Of course, not being able to access more than one drive at a time is a big
> hinderance. But then again, this is the Apple: if we didn't mind in-built
> hinderances and hardware limitations, we'd have upgraded to the Mac years
> ago. :-)

It's been done with USB floppy drives on the Mac...

http://mac-guild.org/raid.html

Of course being able to use a USB hub and having software already 
available helps, along with some processor speed.

Greg B.

-- 
Actual e-mail address is gregbuchner and I'm located at gmail.com