Re: 64-bit kdev_t - just for playing

[Joel Becker]

On Mon, Mar 31, 2003 at 03:41:50PM -0800, Badari Pulavarty wrote:
> I have been playing with supporting 4000 disks on IA32 machines.
> There are bunch of issues we need to resolve before we could
> do that.

	That's the conversation I'm trying to kickstart.

> I am using scsi_debug to simulate 4000 disks. (Ofcourse, I had
> to hack "sd" to support more than 256 disks). Anyway, I noticed
> that I lost almost 350MB of my lowmem, when I simulated 4000 disks.
> We are working on most of these. But there are userlevel issues
> to be resolved. Here is the list ...

	Wow, this is cool.  Thanks for telling me about this.

> I have not done any IO on these yet. When I mount all of these and do
> IO on them, we might see new issues. So with all these, I will be doubtful
> if we can ever reach 16k disks on IA32.

	We're going to have to find a way.  IA32 is going to be around
for long enough, I think.  Easily 8k disks, as soon as the folks who are
doing 4k disks today want to multipath.

Joel

-- 

Life's Little Instruction Book #226

	"When someone hugs you, let them be the first to let go."

Joel Becker
Senior Member of Technical Staff
Oracle Corporation
E-mail: [e-mail]
Phone: [phone]