[parted-devel] msdos logical partition constraints bug in parted

[Phillip Susi]

On 2/6/2011 10:25 AM, Milko Krachounov wrote:
> I created the following partition table with parted (the snipped is *not* 
> actual fdisk output, I edited it by hand)
> 
> {{{
>    Device Boot      Start         End      Blocks   Id  System
> /dev/sdf1            2048      196607       97280   83  Linux
> /dev/sdf4          196608    48859135    24331264   83  Linux
> /dev/sdf3        48859136    60563455     5852160   83  Linux
> /dev/sdf2        60565502  1953523711   946479105    f  W95 Ext'd (LBA)
> /dev/sdf6        60565504    80101375     9767936   83  Linux
> /dev/sdf5        80101376  1953523711   936711168   83  Linux
> }}}

How exactly did you create this, because it appears to be invalid.
There should be a 2 sector gap between the end of sdf6 and the start of
sdf5.  My guess is that the EBR at sector 60565502 contains two type 83
entries for sdf5 and sdf6 instead of one, and another extended entry as
it should.

> Then used to fix the partition order and types with util-linux's fdisk, which 
> not only created a real overlap, it also made the partition table unopenable 
> by parted and applications using libparted. Got the following result (this 
> snipped *is* actual output).
> 
> {{{
>    Device Boot      Start         End      Blocks   Id  System
> /dev/sdf1            2048      196607       97280   fd  Linux raid autodetect
> /dev/sdf2          196608    48859135    24331264   fd  Linux raid autodetect
> /dev/sdf3        48859136    60563455     5852160   fd  Linux raid autodetect
> /dev/sdf4        60565502  1953523711   946479105    f  W95 Ext'd (LBA)
> /dev/sdf5        60565504    80101375     9767936   fd  Linux raid autodetect
> /dev/sdf6        80101376  1953523711   936711168   83  Linux
> }}}

What real overlap did it create?  I don't see one here, though I do
wonder why the tags changed from 83 to fd.  It also still looks like
partitions 5 and 6 are both stored in the first EBR instead of being
chained.