Yes, it's theoretically possible. It's not desirable.

On Thu, 10 Dec 1998, Noriyuki Soda wrote:

> Matthew Jacob wrote:
> > > But, otherwise (e.g. the drivers which handle different HBA), both julian
> > > and CAM scsi middle layer can run at the same time.
> > > Am I misunderstanding something ?
> > 
> > The CAM code also includes target drivers. The paradigms are
> > somewhat different.
> > 
> > It's possible to have config options that compile different classes of
> > files based upon CAM or not-CAM, but doubtful to support them both in the
> > same kernel at the same time.
> 
> Why?
> Theoretically both "sd" of julian and "da" of CAM can co-exist at the
> same time in the same kernel.
> 
> Justin T. Gibbs wrote:
> > You can achieve this only if you give unique names to the peripheral
> > (disk, tape, cdrom, etc.) drivers of both layers.  Either that, or
> > you write a JE->CAM HBA shim and run the old drivers through this
> > emulator.
> 
> In other words, there are two ways coexistence.
> --
> soda
>