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limit disk usage by frontend

Posted: Sat Dec 30, 2017 2:19 pm
by loonylion
Hi, I'd like to request a couple of features that I think should be reasonably simple to implement.


My household consists of four people, my parents, myself and my sister. Currently we have two televisions equipped with old freeview (not HD) HDD recorders. One of these (used by my parents) runs from a roof mounted aerial, the other (used by my sister) has an indoor aerial. My access to TV involves recording programmes on my parent's box and then after they've gone to bed using a capture device to copy them off and then deleting them to free up space.

Reason for implementing MythTV
The OTA signal is really poor where we live, meaning that my sister's aerial needs to be positioned millimetre perfect or she loses channels or the picture gets messed up. My bedroom on the other side of the house has no signal whatsoever. My parent's system works fine unless a pigeon decides to crash land on the aerial, in which case there is momentary signal disruption which recovers shortly afterwards.

There is no cable service here and my dad does not wish to pay for a sky subscription.

The two boxes we are using are showing their age, with my parents' one occasionally exhibiting weird behaviour and has had to be factory reset on at least one occasion. Dad has decided they need replacing, and he'd like a networked system so there's only one recorder box running from the roof mounted aerial and the indoor aerial can be retired.

Implementation details
The system would be based around an AMD APU backend with a TBS quad tuner DVB-T2 card. There would be 3 frontends, one running on the backend machine (at least to start with) and the other two being networked computers.

The Request(s)

My sister is an obsessive recorder of TV. She records everything, her current box is permanently full. We need a means to limit the amount of disk space she is able to use on the backend (and possibly the number of tuners she can use) otherwise no-one else in the house would ever be able to record anything. She will only ever use her own frontend.

On a related note, limiting the view of the record schedules and recorded programs list by default to only show recordings scheduled/recorded by the frontend currently viewing the list. While being able to see the entire collection would be useful on occasion, most of the time my sister's crap would swamp the lists and make it a pain to find anything else.

My Theory

I think this could be implemented by having a frontend table with a unique id and possibly the static ip of the frontends to identify the frontend, and a column storing the disk limit. Then add frontend id in a column against the recordings and recording schedules, when a recording is scheduled an sql query is performed summing the filesizes of recordings made by that frontend id and if its at or above the limit, block the recording with an error. limiting list viewing would be a simple matter of WHERE `frontendid`= id

I could probably do this myself for mythweb if it wasn't object oriented.

Re: limit disk usage by frontend

Posted: Sat Dec 30, 2017 5:23 pm
by pgbennett
You could use a separate storage group, with a separate partition of the appropriate size. However that would reserve an amount of disk space exclusively for those recordings and would not be flexible, to change it would mean repartitioning.
To limit what you see in the frontend you can use recording groups.
You would have to make sure your sister uses a specific storage group and recording group when setting up recording rules. She will likely be tempted to use another storage group when she runs out of storage.

Each frontend already has a unique id in the database (hostname). Your proposal would require a lot of changes in many places. Easier may be a method of enforcing specified recording groups and storage groups.

Re: limit disk usage by frontend

Posted: Sat Dec 30, 2017 6:32 pm
by loonylion
No worries about her being tempted to change storage groups, she's not IT literate enough to dare change anything. The lack of flexibility using the storage group method could become an issue later but would likely work for now.

Re: limit disk usage by frontend

Posted: Sat Dec 30, 2017 11:33 pm
by bill6502
In addition, you can specify how many recordings to keep. And all of
this can be kept in a template. You could change the Default template
to use Peter's suggestions and put the Max to Keep and Max Newest
fields to your liking Or you could leave the Default template as is and make
a new group (called Sis or something) but she'd need to remember to
use it. If you did choose to alter the Default template, then the rest of
the family would have to know how to select another one (perhaps
named Family.

Changing templates doesn't affect existing rules, they're only used at
rule creation time.

Re: limit disk usage by frontend

Posted: Mon Jan 08, 2018 5:24 pm
by PhilB
It is unlikely that you will hit tuner limits with 4 real tuners - in the UK 'multirec' works very well. Each of the real tuners can handle 3 or 4 channels simultaneously from a single multiplex.

When you do start your setup try Gary Parker's pages: