[parted-devel] Problem with cylinder size on SD cards, and other problems

[Marcus Brown]

Hi all,

I've been hacking away at this for a little while now:
http://www.handhelds.org/moin/moin.cgi/RamdiskRescue
which uses parted extensively for a lot of operations.

Recently I realised (while testing smaller cards) that
the cylinder size was defaulting to 8225kB when creating
and new label + partition. Of course, this is way too
large for a 16MB card ;)

The way I've got around this is by using fdisk to create
the label and partition instead, which usually results
in a cylinder size of 32KB. It also takes a lot longer
to execute :(.

I've also had to start working in sectors, rather than
cylinders, which is a bit more painful.


Convert logical to primary
--------------------------
Initially, I had a function (which worked) which was written
because cards formatted by PocketPC contained an extended
partition with a single logical fat32. It worked by performing
a dummy resize of partition 5, removing both table entries,
and creating a new primary with the same start/end as the
previous logical. For some reason this no longer works,
(although I can't tell you when/why it stopped;)
any suggestions on how to do this properly?



Marcus.


ps. hope this is the right list :)