Re: [gentoo-user] Re: [OT] Six non-Gentoo installs

[Rich Freeman <rich0@gentoo.org>]

On Wed, Oct 15, 2014 at 8:14 AM, thegeezer <thegeezer@thegeezer.net> wrote:
> On 15/10/14 04:14, Rich Freeman wrote:
>>
>> One thing I do like is the trend towards putting default configs in
>> /usr and using /etc more for overrides.
>
> you should have a look at unionfs or aufs -- what you can do is have an
> initram that mounts /etc from lvm-stock-etc and then unionfs with
> lvm-custom-etc
> this allows you to have a standard lvm layout everywhere and then only
> need to rsync the lvm-custom partitions
> if you are feeling really fruity could use network locations for the
> stock locations and an sd card or small storage for the custom partition

That could potentially work, but it has some problems:

1.  Updates will get applied to the unionfs, so it will gather
untouched files over time.  That is, unless you unmount the unionfs
before doing updates (which could be difficult if the system is
otherwise operational).
2.  If you modify one line in a file in /etc, the entire file with the
modification will be present in the unionfs.

Using the split /usr - /etc approach usually requires application
support as both configuration files need to be sourced, with specific
settings in /etc overriding those in /usr, but any unmodified settings
being taken from /usr.  Many (most?) packages do not support this.

--
Rich