Re: ext2 on flash memory

From: Eduard-Gabriel Munteanu
Date: Thu Jun 14 2007 - 06:04:55 EST


*This message was transferred with a trial version of CommuniGate(r) Pro*
Juergen Beisert wrote:
So it makes no sense to find the best filesystem for such a case. There is no best one.

It does make sense. Wear leveling isn't the only thing that matters. An important criteria is the total amount of wear that you get when using a filesystem. Some filesystems are simply not suitable: they either write too often to disk (though, as I said, this can be alleviated by COW-ing it or working on a copy and then updating the flash drive), or a single operation requires too many changes to its image/structure. Normal fs-s often change their internal structure, trading for space efficiency or speed. Better storage and accounting of data involve more complicated internal fs structures, that aren't too stable over time (that is, they change often and much).

For example, an ISO9660 multisession rewritable CD/DVD trades space efficiency and flexibility for a lower wear and better wear-leveling. This is obvious, as the user triggers flushes to disk (that is, burning a new session) with a lower frequency, when his work is done, and the writes are always done sequentially (=> wear leveling). I'm not saying anything about UDF, since I don't know much about it.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/