Re: [gentoo-embedded] planning a flash DOM x86 embedded system

[Grzegorz Borowiak]

Every directory, which needs to be writable and persistent, needs to be
mounted as unionfs or AUFS, with one branch in read-only partition, and the
second one somewhere in /var. It's good to mount /etc that way and place
the factory defaults in the read-only branch of this. An alternative is to
allow only several files in /etc to be writable and move them to someplace
in /var (e.g. /var/etc) and leave symlinks in /etc (e.g. /etc/resolv.conf
-> /var/etc/resolv.conf).


On Wed, Oct 16, 2013 at 2:48 PM, Francisco Ares <frares@×××××.com> wrote:

> Hi.
>
> I am planning to build a system to be deployed in a SATA flash disk, and
> most of the file system will be read-only. There will be a tempfs on /temp
> and a read-write partition for /var (perhaps a unionfs with the static part
> of /var and that read-write partition)
>
> Is there any resources on how to do this using Gentoo?
>
> There is already a development system with everything working as expected
> on the final system. But when I put it to a squashfs, the system boots with
> several errors, like when trying to write to /etc and /var.
>
> Looking on the new issue regarding /usr and / being on a different
> partitions, I have found the file in /etc/initramfs.mounts. I have added
> the needed fstab entries to be mounted before the system switches to the
> real-root, (as the comments on top of this file claims)  but there are
> still errors during boot.
>
> Thanks
> Francisco
>