On Saturday 19 March 2011 07:48:05 srimugunthan dhandapani wrote:
> Hi all ,
> This is my first mail to the yaffs group. I am learning yaffs file
> system and i have some doubts trying to understand checkpointing and
> how yaffs copes without having a on-disk format.
>
> 1. On mounting how is the starting of the checkpoint block located. I
> guess it should be at a fixed location on flash as we cant scan for
> the checkpoint start block. Then if we use the same block for
> checkpoint wont it hurt the wear of that particular block?
It is not at a fixed location but has to be found by scanning.
> 2. Is the checkpoint information stored contiguously on the flash or
> is it scattered ?
It might be scattered.
> 3. Where is the super block stored on the flash?
There is no superblock.
> 4. When we open an existing file how do we get the tnode information?
> When checkpointing does the tnode structure of all files also
> checkpointed?
Yes the checkpoint info stores the info in tnodes.
> 5. Roughly how much RAM will be needed for a 512 GB flash assuming it
> stores 1000 files with size of 500MB each.
I have not tested yaffs with that much flash and there might be some issues,
It would need a lot of RAM - many hundreds of Mbytes.
-- CHarles
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