Hi,

I would like to resize up a partition in a special use case.

I have a 256MB nand chip with 2 yaffs partitions
/boot of 32MB - nand blocks from 1 to 261
/usr of 128MB - nand blocks from 262 to 1290
nand blocks from 1291 to 2047 was never used and are clean
The resize will be done only once and at boot time. /usr will be increased to 224MB (blocks from 262 to 2047)

Because of yaffs2 architecture, do you think it is possible to resize up "/usr" partition without any issue on filesytem ?

Jean-Christophe
PS: my operating system is vxWorks

Yes it is very possible to do this, but there are some important issues to doing this properly.

Let us assume you're doing this while the Yaffs partition in NOT mounted, just to make things simpler...

1) Make sure the blocks you add are erased (or bad blocks). If you add blocks with data in them, then that will cause confusion.

2) Make sure the first time you mount after the change that the checkpoint is not used. This can be achieved by one of:

a) Set flags so that the checkpoint is NOT saved.

b) Set flags so that the checkpoint is ingroed when booting.

If your system never writes a checkpoint (eg you always kill power and never do unmounts or other checkpoint writes) then you do not need to worry about (2). If that is the case, and the blocks were never written, then just expand the partition size and your job is done.

You can even do a resize down of the file system, but that is a little more complicated.

-- Charles