Re: jffs2 and kernel config for SDHC Memory Cards

[Sitsofe Wheeler]

On Fri, Mar 06, 2009 at 03:56:01PM +0200, Thanasis wrote:
> on 03/06/2009 03:39 PM Thanasis wrote the following:
> > I want to use two of these Transcendâs Class 6 SDHC (SD High-Capacity)
> > Memory Cards,
> > http://www.transcendusa.com/Products/ModDetail.asp?ModNo=147&LangNo=0&Func1No=1&Func2No=13
> > as part of the filesystem in a netbook (Acer A110L), will mount /home on
> > one, and /tmp and /var on the other.
 
> Let me rephrase my questions in order to be clearer:
> Q1: In order to achieve wear leveling should I format them as jffs2?

This probably won't be very effective as you are already past the
anecdotal size recommended for jffs2 partitions (I've heard rumours that
it is best suited to filesystems that are less than 64Mbytes and another
that says less than 1Gbyte). Additionally you are not providing direct
access to the raw flash (see
http://linux-mtd.infradead.org/faq/jffs2.html#L_stick_jffs2 ).
Performance is probably not gong to be very good.

> Q2: In order to achieve wear leveling, any specific options I should
> enable in kernel (2.6.28) configuration?

You will be wear levelled by the hardware anyway as the hardware only
provides a block device interface and you don't have access to the raw
flash. 

ccing Dave Woodhouse as he is the JFFS2 creator.

-- 
Sitsofe | http://sucs.org/~sits/
--
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/