[mythtv] Possible Future Option?

Matt Zimmerman mythtv-dev@snowman.net
Sat, 30 Nov 2002 11:55:42 -0500

On Sat, Nov 30, 2002 at 08:07:55AM -0800, Harondel J. Sibble wrote:

> On 30 Nov 2002 at 0:54, Matt Zimmerman wrote:
> > I understood fine, but I cannot think of a realistic situation where would be
> > useful to me.  Why would you want to place different recordings under
> > different paths?
> I can think of a few:
> 1) You have an external/removable/portable hard drive - firewire, USB2.0 etc

And?  Either you want recorings to go directly to that drive, or not.  If
you plan to remove it, you don't want scheduled recordings to go to it.  You
would record to a fixed disk and then copy the recordings if you wanted to
take them somewhere.

> 2) In relation to the separate encoder and decoder, you could write files to 
> a local drive and when that's full, write to the network and/or vice versa.

What's the benefit of this setup?  If your goal is to play back content from
the local drive when possible, it would be better implemented as a cache
than letting it overflow onto another system.

> 3) You add a second drive and want to alternate recording between drives., 
> Say all Buffy shows on drive 1 and all Angel shows on drive 2 etc


> Plus, setting up LVM is more reading and work and also if one f your
> drives dies in an LVM setup, you could potentially lose a lot of depending
> on how you are setup. In the case that started this thread, you lose the
> contents on one but have the stuff on the second or thirs or whatever
> drive.

In a concatenated volume, you generally lose all files which have blocks
stored on the failed disk (the other parts of the file are recoverable, but
this is usually not interesting unless the data is critically important).
In a one-filesystem-per-disk setup, you lose all files which are stored on
the failed disk.  These scenarios could be identical or different, depending
on the filesystem.

In any non-redundant setup, you are going to lose data when a disk fails.
TV recordings are not generally mission-critical anyway.

 - mdz