[mythtv-users] My schedule got deleted on upgrade!

Michael T. Dean mtdean at thirdcontact.com
Sun Mar 25 18:09:48 UTC 2007

On 03/25/2007 11:45 AM, Rod Smith wrote:
> On Saturday 24 March 2007 23:11, Michael T. Dean wrote:
>> If your capture card/drivers change, you'll need to delete and re-add
>> capture cards /and/ video sources.  You should also use the Delete All
>> buttons to delete them; otherwise, you'll leave old data there that will
>> likely cause problems.
> If by this you mean that you've got to assign video sources to input 
> connections using the Input Connections section of mythtv-setup, I agree. If 
> by this you mean you must delete and then re-create all your video sources 
> using the Video Sources section of mythtv-setup, then please elaborate.

Basically, if you need to change your video source, the best approach is 
to Delete All video sources and re-create video source, input 
connections, and channels.*  If you need to change your capture 
card/drivers, the best approach is to Delete All capture cards /and/ 
Delete All video sources and re-create capture cards, video sources, 
input connections, and channels.**

Why?  (a.k.a. "The Delete-All Manifesto")

If someone sends me a MS Word document that I'm supposed to edit and/or 
format, the first thing I do is save it as plain text and then edit and 
properly format the unformatted version.  It's easier to ensure 
everything is done properly if you start from a clean state--rather than 
trying to undo what's wrong and do what's right.  (And, since MS Word > 
2.0 has stopped trying to get people to properly format their documents 
and instead has changed "auto-whatever" to format docs the incorrect way 
most users did with MS Word 2.0 (i.e. Tab-Tab-Tab, Enter-Enter-Enter, 
everything default style, ...), you're almost guaranteed that any 
document you get is not clean to start with, but that's a whole 
different story.)

Likewise, with Myth configuration--which, IMHO, is much more important 
than a cleanly-formatted Word document--the best way to ensure 
everything is cleanly-configured is to start from a clean state.  The 
more things change, the more likely starting from a clean configuration 
is /required/ (as opposed to just A Good Thing).***  When drivers 
change, you can take a chance that the old configuration might work, or 
just Delete All and reconfigure.  Even if most upgrades work without 
issue, once you start MythTV and find there are no available capture 
cards, the first thing you should do is Delete All.

Also, recreating video sources, input connections, and channels all 
together ensures that the user verifies every aspect of the 
configuration.  Most questions users have when changes to these areas 
don't fix the problem are due to the fact that they missed some small 
value that also needed changing--perhaps in a section they thought would 
be unaffected.****

Delete All also has the benefit of resetting capture card, video source, 
and channel ID's.  Therefore, when using Delete All, the OC crowd 
doesn't worry about, "I only have 2 cards, so why does the status page 
call them, 'encoder 1' and 'encoder 26'?"

Also, using Delete All to reconfigure everything every once in a while 
ensures that you remember how to configure the system, so in the event 
of catastrophic failure, you're not starting from ground 0.  Instead you 
have some MythTV configuration knowledge in your toolbox.  If you 
configure your Myth box, run it for 4 years, lose a DB, and try to set 
up a new box, you're likely to spend a lot of time trying to remember 
how you had configured it last time.

And, lastly, using Delete All and re-creating everything takes about 2 
minutes.  Changing miscellaneous values, testing, finding it doesn't 
work, changing more values, testing, checking the list archive, 
Googling, writing a message to send to the -users list, and waiting for 
some kind soul to spend >2 minutes to read your post and write a 
response (even if it's just the "Use Delete All to delete your video 
sources and then re-create video sources, input connections, and 
channels" post), takes a *bit* more than 2 minutes.

I'd even venture to say that it's quite likely to take longer to dig 
through the setup screens to find the right value(s) to change while 
verifying the existing values than to simply Delete All and 
re-configure.  The /only/ way it could possibly be faster to change 
individual values is if you get /everything/ right the first time (and 
if you find things quickly).  In the end, though, you took a risk that 
saved you some amount of time less than 2 minutes.  Not, IMHO, a good 
cost-benefit ratio.

If you completely understand all of the requirements of capture 
card/video source configuration (i.e. the rules in place in the code) as 
well as the linkage of the different pieces of data (both to other data 
and to the code), and the effects of changing each piece of data, feel 
free to change the occasional value.  But, if after I suggest Delete 
All, someone tries a different approach "because the 2-minutes to 
re-create everything is too tiresome," he/she shouldn't be surprised 
when I fail to reply again if there are still issues.  ;)  I've been in 
the MythTV code--through many sections that describe the rules for this 
data--and I have a pretty good understanding of the data, but I /still/ 
use Delete All.

(Well, you /asked/ me to elaborate...)


* "mythfilldatabase won't add channel X to my video source."
  "I deleted a channel, but it keeps coming back."
  "I added a channel, I can see it in LiveTV, but when I try to schedule 
a recording from that channel, it doesn't record anything."
  "My cable company re-numbered all my channels, so I changed them in 
the DB/mythtv-setup/MythWeb and now my scheduled recordings don't work."

** Television/Tuner 0

*** Sometimes changes require data modifications that cannot be made 
through the mythtv-setup UI.  Changing values directly in the database 
is always the wrong solution ( 
http://www.gossamer-threads.com/lists/mythtv/dev/255378#255378 ), so the 
only supported approach is using Delete All and re-configuring from 
scratch.  (Why not make all values editable directly in MythTV?  Hmmm.  
Good point.  Perhaps MythTV configuration isn't complex enough... ;)

**** "It didn't work the first time, but when I used "Delete 
All"/dropped the database and re-did it, it worked!"  (Since Myth isn't 
changing when someone drops the database, do you want to guess what does 

More information about the mythtv-users mailing list