slow FC4 to FC5 upgrade

[Paul Howarth]

On Sun, 2006-03-26 at 03:05 +0930, Tim wrote:
> Tim:
> >> I am curious as to why DMA might foul up mediacheck or installations,
> >> but be okay once you have an installed system? 
> 
> Paul Howarth:
> > The kernel code for detecting the end of the data on an IDE CD doesn't
> > work reliably when DMA is on.
> 
> Hmm, sounds like something that ought to be fixed, rather than worked
> around.  Surely it's possible?

I'd have thought so, but it's probably not a big issue for the kernel
guys because it's hardly ever necessary to have to detect the end of the
media for a CD/DVD - the filesystem format indicates how big everything
is and you just stop reading when you've read the real data normally.
When you're pulling the data from the raw device, you don't have the
filesystem metadata and so you don't know how big it is.

This has been an issue ever since FC3, maybe even FC2, so I'd guess it's
not a trivial problem to fix.

Paul.