Re: Driver for emulating a tape device on top of a cd writer...

Jens Axboe
2000-12-18T18:35:41Z

On Mon, Dec 18 2000, Stelian Pop wrote:
> Hi folks,
>
> I've got this idea some time ago, thinking it would really be
> a neat thing...
>
> Basically, I would like to be able to use a cdwriter as a tape
> device, with software like dump(8) or tar(1). With /dev/tcdw
> as name (for example), I'd like to be able to do:
> mt -f /dev/tcdw rewind
> tar cvf /dev/tcdw /
> tar cvf /dev/tcdw /home
> mt -f /dev/tcdw rewind
> mt -f /dev/tcdw fsf 1
> tar xvf /dev/tcdw
> ...
>
> As someone said to me, this seems to exist on some other UNIX
> system (don't recall if it was AIX or something else)... But
> I didn't find any work on Linux in this direction.

What you describe is actually one of the goals of the packet writing
driver. To do this reliably you need packet writing, I won't even
start to think about the headaches wihtout it...

> I'll start to work on this, probably by looking at the cdrecord
> low level code and porting it into kernel space.

Oh god no! You can do all this from user space.

--
* Jens Axboe <axboe@suse.de>
* SuSE Labs