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Subject: Re: ubifs version 1 compatibility
From: Artem Bityutskiy <dedekind@infradead.org>
To: Hamish Moffatt <hamish@cloud.net.au>
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Date: Thu, 26 Mar 2009 14:12:05 +0200
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On Thu, 2009-03-26 at 23:04 +1100, Hamish Moffatt wrote:
> On Thu, Mar 26, 2009 at 11:50:23AM +0200, Artem Bityutskiy wrote:
> > On Thu, 2009-03-26 at 18:44 +1100, Hamish Moffatt wrote:
> > makes it very difficult to turn old image into new one. This will
> > basically mean we need:
> > 
> > 1. extract files from the old image
> > 2. feed them to mkfs.ubifs.
> > 
> > > Maybe before upgrade we could run mkfs.ubifs using the contents of the
> > > existing volume to create the new format, unmount it and ubiupdatevol it..
> > 
> > The easiest way to do this is to boot the old kernel,
> > e.g. in vmware, extract the files using the nandsim technique:
> > http://www.linux-mtd.infradead.org/faq/ubifs.html#L_ubifs_nandsim
> > 
> > then feed them to mkfs.ubifs.
> 
> Well I have these files on embedded devices out in the real world. The
> volume is storing user data, so I need to do this change in-place.

Let me make sure I understand the need.

So you have devises with v1 format in the wild. You want to upgrade
those devices. While upgrading, you will re-write some UBI volumes, but
after upgrade the user-data volume should contains exactly the same data
as before the upgrade, right?

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)