[Unionfs] Re: unionfs, cow, and whiteout

[Paul Albrecht]

On Thu, 2008-01-17 at 00:33 +0100, pascal at pabr.org wrote:
> Paul Albrecht wrote:
> > I think the 2-branch configuration where one branch is ro and the other
> > is rw is the normative case and the other scenarios are more
> > hypothetical than real world.
> 
> I am trying to use unionfs for hierarchical storage management:
> Multiple rw branches, each with distinct storage type and
> backup policies.  I want to explicitly assign files and
> directories to specific branches.  For example:
> 
> myproject/src/        on a RAID1 array with weekly snapshots.
> myproject/downloads/  on a regular disk with monthly backups.
> myproject/build/      on a fast disk without backups.
> 
> This is actually much simpler than a liveCD - whiteouts and CoW
> are not even needed.  But unfortunaly some recent simplifications
> have made it harder to use unionfs with multiple rw branches for
> this kind of application.
> 
> So please do not focus too much on the liveCD scenario !
> 

If you're unconvinced that the liveCD scenario is normative check out
the unionfs home page which lists projects presently using unionfs.

> Regards,
> Pascal
> 
> _______________________________________________
> unionfs mailing list: http://unionfs.filesystems.org/
> unionfs at mail.fsl.cs.sunysb.edu
> http://www.fsl.cs.sunysb.edu/mailman/listinfo/unionfs
-- 

Paul Albrecht