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Date: Fri, 04 Dec 2009 13:38:31 +0200
From: Adrian Hunter <adrian.hunter@nokia.com>
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To: twebb <taliaferro62@gmail.com>
Subject: Re: how to properly calculate max-leb-cnt and vol_size for ubifs
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twebb wrote:
> I'm using ubifs for the first time and am confused about how to
> calculate two parameters:
> 
> "max-leb-cnt" for mkfs.ubifs
> "vol_size" for ubinize cfg file
> 
> How should "max-leb-cnt" be calculated?  In the examples, how is "-c
> 2047" determined?  Should the max-leb-cnt calculation somehow include
> the overhead calculated per the ubifs documentation page?  Should the
> reserved PEBs (1% default for NAND flash) be somehow taken into
> account?
> 
> How should "vol_size" be calculated?  Is it simply max-leb-cnt *
> LEB_size?  Should overhead somehow be included in this calculation
> also?

Have you read:

http://linux-mtd.infradead.org/faq/ubifs.html#L_max_leb_cnt

http://linux-mtd.infradead.org/faq/ubi.html#L_ubi_mkimg

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