[mythtv-users] Storage group question

[Michael T. Dean]

On 01/14/2013 10:51 AM, Joseph Fry wrote:
>>> Oh, and if two storage groups contain the same path... I'm not exactly sure
>>> if mythtv will properly report the storage group for the individual
>>> recordings.  For example if both the 'default' and 'sports' storage groups
>>> share a particular folder, you may find that the recordings to the
>>> 'sports'
>>> storage group will report that they are in the 'default' storage group.  I
>>> know that mythtv will allow recordings to be moved around the file system,
>>> thus between storage groups, so I suspect that it will detect all
>>> recordings in a particular folder as being part of just one storage group;
>>> not both.
>> It actually stores the Storage Group with the recording metadata, but
>> never stores the physical location.  Therefore, MythTV would always report
>> the correct Storage Group, even if there's overlap of directories among
>> Storage Groups.  That said, you're probably right that the Sports Storage
>> Group (at least as described/envisioned) probably isn't necessary, and my
>> other reply gave Paul a couple other, probably better, options for
>> achieving what it looks like he wants.
> Thanks for the clearification Mike... I suspected that it did store the
> storage group in the metadata... but then I recalled that mythtv will let
> you move a recording from one storage group to another (at least at the
> file system level).  Does it preserve the storage group even if the current
> folder containing the recording isn't part of that storage group?

Yes, so if you move it from a directory in Default to a directory that's 
only in, say, Archive, it will still show as being "in" the Default 
Storage Group--though it's finding it in another directory.

Similarly, if your Default Storage Group contains the directory 
/srv/mythtv/tv/c/recordings, today, and MythTV records a new recording 
to that directory, and tomorrow you edit the directory list for Default 
to no longer contain the /srv/mythtv/tv/c/recordings directory, the 
recordings is still "in" the Default Storage Group, even though it's in 
a directory that's no longer in that Storage Group.

Storage Groups are simply used a) as a way to command MythTV where to 
write a recording and b) as a hint about where to find a recording once 
it's recorded--to order our directory search for the recording file.  
But, since changing the hint doesn't have any appreciable performance 
benefit, there's no reason to update it when you move the recording 
file.  In the future, though, we'll have a better 
(specific-to-the-directory-level) hint for where to find the recording 
file, and that will be updated (automatically) when the recording 
moves.  At that point, the Storage Group will really only mean anything 
to the recording rule, and not the recording itself.

So, really, Storage Group has little meaning once a recording is 
recorded, which is why the vast majority of users probably only ever 
need a Default Storage Group (for writing TV recordings) and, possibly, 
an Archive Storage Group (for storing recordings on a "safe" file system 
that won't ever experience auto-expiration)--in addition, of course, to 
the "special" Storage Groups used by, for example, Video Library or DB 
Backups or whatever.

Mike