[wellylug] Fsck'd Partitions... help?

[David Antliff]

On Fri, 21 Apr 2006, Cliff Pratt wrote:
> mmmm. The partition numbers make me think that the missing partition should 
> be hdb3 and hdb4. The extended partition probably should include both hdb5 
> and hdb6 so should be 9 + 86 = 95Mb shouldn't it?

DOS partition table tools (like fdisk) only allow one extended partition 
record in the main partition table, and it must be the last one defined (I 
think), so it's typical to have a primary partition, an extended + logical 
partitions, then two primary partitions at the end. So if partition 2 is 
his extended partition, then 3 and 4 would be tricky to create. I'm not 
sure what happens if you actually DEFINE these however...

The first extended partition is numbered '5' regardless of the number of 
physical partitions defined - because 1-4 are reserved for primary 
partitions.

Looking directly at the main partition table might help: It's at offset 
0x1b0 on /dev/hdb btw, so rows 3 and 4 start at 0x1d0 and 0x1e0 
respectively. You should see an 0xaa55 at 0x1fe.

These may be useful:

http://www.win.tue.nl/~aeb/partitions/partition_tables.html
http://www.partitionsupport.com/partitionnotes.htm

Remember that Linux doesn't use the CHS values in the PT records - it just 
uses the sectors (and is therefore quite straightforward to decode).

-- 
David.