On Sun, Nov 24, 2013 at 05:52:26AM -0800, Marc MERLIN wrote:
> Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
> 255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
> Units = sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disk identifier: 0x0b8ccbaa
>
> Device Boot Start End Blocks Id System
> /dev/sda1 2048 1050623 524288 83 Linux
> /dev/sda2 1050624 105908223 52428800 0 Empty
^^^^^^^^^^
Congratulation, you found very old fdisk bug as well as GNU Parted bug :-)
The problem is that the partition has no set partition type, and
fdisk in some situations interprets such partition as unused.
So it lists the partition (print command), but the "add new
partition" command interprets this partition as unused.
> Command (m for help): n
> Partition type:
> p primary (1 primary, 0 extended, 3 free)
> e extended
> Select (default p): p
> Partition number (1-4, default 3):
> Using default value 3
> First sector (1050624-1953525167, default 1050624): 105908224 << eek default is bad
Yep.
It seems that GNU Parted is more consistent, it ignores the partition
at all :-), for example:
# fdisk -l /dev/sdb
...
Device Boot Start End Blocks Id System
/dev/sdb1 2048 22527 10240 83 Linux
/dev/sdb2 22528 227327 102400 0 Empty
# parted /dev/sdb print
...
Number Start End Size Type File system Flags
1 1049kB 11.5MB 10.5MB primary
This is definitely bug too, because Linux does not care about
partition type and kernel is able to use this partition:
# lsblk /dev/sdb
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 600M 0 disk
├─sdb1 8:17 0 10M 0 part
└─sdb2 8:18 0 100M 0 part
Note, don't use -S and -H, fdisk does not care about CHS by default
(you have to enable obsolete DOS mode ('c' command)).
I'm going to make fdisk more robust and prepare also a patch for GNU
parted.
Thanks!
Karel
--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com
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