Subject: Re: compressed device layer
To: None <dlagno@mail.nnov.ru>
From: Julio M. Merino Vidal <jmmv@menta.net>
List: tech-kern
Date: 04/24/2004 16:29:31
On Sat, 24 Apr 2004 18:12:04 +0400
"Denis Lagno" <dlagno@mail.nnov.ru> wrote:

> Hi,
> 
> I am thinking about compressed block device layer -- implemented in much
> the same fashion as cgd/ccd/vnd.
> This layer will use some underlying device and provide virtual block device of larger size.
> It will store its content on underlying device in compressed form.
> Compression will probably be per block basis.
> In case compression ratio appears to be overestimated and real device got full,
> layer would issue error notification to syslog and fallback to use swappable memory to
> store its content.  This point of its behaviour is the most obscure for me currently.
> 
> How do you think can this layer be useful?  Is it worth implementing?

If this can be applied to cdroms, yes.  It could be very useful to create
live cds, where the space is kinda limited...

-- 
Julio M. Merino Vidal <jmmv@menta.net>
The NetBSD Project - http://www.NetBSD.org/