Re: bios - Re: GRUB problem (long, description of BOOT)
Alvin Oga wrote:
On Wed, 28 Sep 2005, Mike McCarty wrote:
Yes, I'm talking about servo data, which cannot be seen
by dd or any other normal (or even driver level) accesses.
i think we;re talking about the different kidns of servo
data ... created/maintained at different levels
and i'm not talking about file system junk either
but it doesnt matter ... my point is different
apps plays with different data .... and is NOT
jst the factory ( wd, maxtor, seagate ) that can
create these "servo data"
sure it can ... try it ... the servo data is gone
that track-1234 head-6 sector-47 is not longer
marked as bad block because dd overwrote it
Certainly it can write to the "reserved" areas of the
disc (I mean reserved by the file system).
you keep going to filesytem
No, you do.
there is reserved space for servo dta too as you noted
and that data can be over written by dd depending
on its purpose and where and when it is written
But it cannot
write to the servo area (which is used by the uC on the
disc to ensure proper head alignment).
am not talking about the head alignment and gaps or anything
But I am, and was, and have been, and have been trying
(unsuccessfully) to point that out. The head alignment
(servo) information cannot be diddled by dd. The low-level
format information is not accessible to high-level programs
(like dd). It requires special interface. One cannot clobber
the sector formatting by using dd, which sits on top of
This is probably as far as we can (profitably) go.
This message made from 100% recycled bits.
You have found the bank of Larn.
I can explain it for you, but I can't understand it for you.
I speak only for myself, and I am unanimous in that!