[OpenAFS] Re: vos shadow to backup user homes

Andrew Deason adeason@sinenomine.net
Mon, 26 Aug 2013 15:11:47 -0500

On Mon, 26 Aug 2013 14:24:32 -0400
Jeffrey Hutzelman <jhutz@cmu.edu> wrote:

> > Yes, one of the downsides of shadow volumes is that using them is
> > not documented as well as other features, and they aren't tested as
> > much. 
> Because there actually is no such feature as a "shadow volume".
> Manual pages notwithstanding, the "vos shadow" command does not
> "create a shadow volume";

That's not why; the fact that there is no feature known as a "shadow
volume" in the AFS protocol (though there most definitely is such a
feature in the openafs codebase) is a technical detail and has nothing
to do with it. Nothing stops us from writing pages and pages of
documentation detailing how to make use of shadow volumes in various
setups. Nothing stops us from writing numerous vigorous tests for the
"vos shadow" command, or for other commands interacting with volumes
created by such a command.

The only relevance to a user I can see regarding this technical detail
is that it's less likely to break between releases, though more likely
to confuse other tools unrelated to releases. Although it can and has
had issues independent of move/release/etc, that's probably more rare
than if something like 'vos shadow' did something involving a completely
different implementation.

Andrew Deason