ubifs: partition won't mount: duplicate sqnum in replay ???

[Artem Bityutskiy]

On Tue, 2008-12-30 at 07:11 -0500, Cal Page wrote:
> I'm running ubi at 2.6.27.4, ubifs is a mix of that base plus some 
> 2.6.21 as the vfs interface changed. There are only three mtd calls you 
> make, so that rev just isn't important. The base kernel, and most of vfs 
> is at 2.6.19.

Not sure I understand this.

> I did not initialize the nand for the unit in question. It could have 
> been the problem. I'll re-format it and start again. But, for testing, 
> we have a 'crasher' device that randomly crashes the file system to 
> force us into difficult recoveries. In short, for ubifs to be shipped, 
> it must survive and re-mount AFTER EVERY CRASH, period.

Fair enough. We did similar tests at our side.

> The only other problem is that ubifs takes way too much memory.

You use olde kernel, and UBIFS shrinker is disabled there, which means
that it never flushes the TNC cache. This is noted here:
http://www.linux-mtd.infradead.org/doc/ubifs.html#L_source

>  We run 
> for a few days on our 1 gb nand, and then the oom_killer gets called and 
> down we go. What exactly was done in later releases to fix this? I need 
> to back-port a solution before we ship.

The TNC shrinker is registered. See 'ubifs_shrinker()'.

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)