Poettering: Revisiting how we put together Linux systems

Posted Sep 3, 2014 0:21 UTC (Wed) by kreijack (guest, #43513)
In reply to: Poettering: Revisiting how we put together Linux systems by ofranja
Parent article: Poettering: Revisiting how we put together Linux systems

> It seems to me that everything outlined in this article can be already
> done by using bind mounts (w/some specialized filesystem hierarchy), LVM
> (for snapshots) and namespaces/chroot.

The snapshots have a totally different scope: they are needed to take a *atomic* photo of a filesystem.
For what Lennart needed it is more simple to hardlink the common files during the "package" installation: you need a database of the hash and the path, when there is an hash collision you create an hard link instead of a copy of the file. This should work because these trees are RO.

Poettering: Revisiting how we put together Linux systems

Posted Sep 3, 2014 18:09 UTC (Wed) by ofranja (guest, #11084) [Link]

That's what snapshots are for, atomic photos of the system.

The specific technology used is actually not that important, as long as it stays as a different layer - if you are creative enough, you could even use union mounts for that.

My point is: there are mechanisms to implement snapshots which do not create any dependency on a specific filesystem feature.

You might not agree that this is important - but for me, it's a must.