ubiattach taking very long time

[Artem Bityutskiy]

On Tue, 2009-12-22 at 09:14 -0500, twebb wrote:
> Does it make any sense that a ubiattach would take > 20 secs?  The
> flash I'm using is Samsung 4GiB MLC NAND flash.  I'm running 2.6.28
> kernel.  Here's the capture...

Yes, it can do this. UBI is not scalable, read here:

http://www.linux-mtd.infradead.org/doc/ubi.html#L_scalability

Please, also take a look here:
http://www.linux-mtd.infradead.org/faq/ubi.html#L_attach_faster

To really fix your problem we need UBI2.

In your case, it needs to read 8KiB from each PEB. If you know your I/O
speed, you can do the math.

To measure your read speed and scan speed, you can use 'mtd_speedtest':

http://www.linux-mtd.infradead.org/doc/general.html#L_mtd_tests


-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)