[NTLUG:Discuss] cfdisk and bootable partition flag

[ntlug@levelofdetail.com]

Thanks for previous replies. Very helpful.

Below is the fdisk output. hda and hdb look a lot alike because I dd hda
to hdb for backup purposes. (Not the most efficient, I know, but it's
just a home machine.)

-------
Disk /dev/hda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1               1         129     1036161   82  Linux swap /
Solaris
/dev/hda2             130        5351    41945715   83  Linux
/dev/hda3            5352        7310    15735667+  83  Linux
/dev/hda4            7311        9728    19422585   83  Linux

Disk /dev/hdb: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hdb1               1         129     1036161   82  Linux swap /
Solaris
/dev/hdb2             130        5351    41945715   83  Linux
/dev/hdb3            5352        7310    15735667+  83  Linux
/dev/hdb4            7311        9728    19422585   83  Linux
-------

The things that originally got me wondering what heck is going on were:

1. Neither fdisk nor cfdisk indicates a bootable partition. From
previous posts I gather that Grub on the MBR points to the location (a
physical hd location, not logical) of Grub on the boot sector of the
bootable partition. I assume, then, that a bootable flag is not even
needed and wasn't set on installation. (SUSE 9.2)

and then some weirdness -

2. If I  cfdisk -P /dev/hdb, the cfdisk header indicates that I'm
looking at hda. (Really!) From the header:

cfdisk 2.12c
Disk Drive: /dev/hda
Size: 80026361856 bytes, 80.0 GB
Heads: 255   Sectors per Track: 63   Cylinders: 9729

Does it say "/dev/hda" because /dev/hdb is a dd copy of /dev/hda? My
theory - when I dd the entire disk, I'm dd'ing "I am hda" to hdb
somewhere and cfdisk is picking that up rather than reporting its
physical location, which we already know because that's what we asked
for in the first place.

(By they way - cfdisk -P /dev/hda shows that it is /dev/hda also.)

Thanks again.

Ed

On Thu, 2006-01-12 at 09:24 -0600, Terry wrote:
> On 1/12/06, Terry <trryhend at gmail.com> wrote:
> > On 1/11/06, ntlug at levelofdetail.com <ntlug at levelofdetail.com> wrote:
> >
> > >
> > > Another curiosity -
> > >
> > > When I
> > >
> > >    cfdisk -P /dev/hdb
> > >
> > > the header info of cfdisk indicates that I'm look at /dev/hda.
> > >
> > > Any help is appreciated.
> > >
> > > Ed
> >
> > How many hard drives do you have in this computer?
> >
> 
> I'm sorry, I wiped out the first line that says that you have two hard
> drives.  But, I'm not sure what to make of it what you say,
> "the header info of cfdisk indicates that I'm look at /dev/hda"
> I think you'd have to give us a little more information about your
> computer before we can determine what "cfdisk -P /dev/hdb" is telling
> you about your system.
> 
> In other words give us the exact output of "cfdisk -P /dev/hdb" and
> then "cfdisk -P /dev/hda" as well, so we can compare and understand
> better.
> 
> Actually, I'm more familiar with fdisk, and would probably understand
> it's output better, so why don't you try
> fdisk -l /dev/hda
> &
> fdisk -l /dev/hdb
> and see if that gives you or us information we need.