[mythtv-users] Migration question from 0.24 to 0.25

Michael T. Dean mtdean at thirdcontact.com
Mon May 21 17:20:09 UTC 2012


On 05/19/2012 11:14 PM, eric millham wrote:
> Hi, I'm on Ubuntu 12.04.
>
> I've bought a spanking new HTPC and want to copy myth from my old HTPC 
> and not mess with the old one till the new one is working 100%
> So, I figured I would copy over mythconverg and then run myth setup to 
> migrate it.
> But I get errors because I'm 17 schema levels back:
>
> /2012-05-19 20:44:55.360474 C  MythTV database schema is old. Waiting 
> to see if DB is being upgraded./
> /2012-05-19 20:44:56.362775 I  Current MythTV Schema Version 
> (DBSchemaVer): 1276/
> /2012-05-19 20:44:57.364872 I  Current MythTV Schema Version 
> (DBSchemaVer): 1276/
> /2012-05-19 20:44:58.366925 I  Current MythTV Schema Version 
> (DBSchemaVer): 1276/
> /2012-05-19 20:44:59.369219 I  Current MythTV Schema Version 
> (DBSchemaVer): 1276/
> /
> /
> /This version of MythTV requires an updated database. (schema is 23 
> versions behind)/
> /
> /
> /Please run mythtv-setup or mythbackend to update your database./

Note that 1276 is not a valid schema version for any released version of 
MythTV.  Therefore, assuming you weren't running some random (old) 
unstable/development version of MythTV, you attempted to run MythTV 
(mythtv-setup or mythbackend) and it attempted to update your database, 
but failed after the 1276 update.  That means that the database state is 
undetermined and should never be trusted.

Any time you have a failed database upgrade, you should always restore 
the pre-upgrade backup of the -fixes (I'm assuming 0.24-fixes, which 
means a schema version of 1264) database and then fix whatever issue is 
preventing the upgrade and then upgrade.  Based on what, specifically, 
the 1277 upgrade is doing, I'm assuming the only reason it failed is 
because someone/some-broken-script killed mythbackend (or mythtv-setup) 
while it was working on the upgrade.

I highly recommend shutting down all MythTV applications (frontends and 
backends and mythtv-setup) and restoring the 0.24-fixes database backup 
( 
http://www.mythtv.org/wiki/Database_Backup_and_Restore#Replacing_an_existing_database 
), then running mythtv-setup to upgrade the database, and waiting 
patiently for it to finish.  (You can view the log output on the console 
to see it progressing through the upgrades.)

Note that if you didn't do a database backup before attempting to 
upgrade, MythTV will attempt to create one for you.  However, it sounds 
like your production system is still running properly, so you 
could/should just create a new backup on it ( 
http://www.mythtv.org/wiki/Database_Backup_and_Restore , where the first 
2 (small) sections should help you create the backup).

> /
> /
> /Database Host: localhost/
> /Database Name: mythconverg/
> /
> /
> /2012-05-19 20:45:00.371248 I  Current MythTV Schema Version 
> (DBSchemaVer): 1276/
> /2012-05-19 20:45:00.371314 C  Timed out waiting./
> /2012-05-19 20:45:00.371350 E  Not allowed to upgrade the database./
> /2012-05-19 20:45:00.372423 E  Couldn't upgrade database to new schema/

That happens when you try to upgrade using mythbackend on some host 
other than the master backend or using mythfrontend on any host.

> Is there a way to do this?

The above instructions will tell you how to better/more successfully 
upgrade the database.

Once complete, however, it's quite likely that you'll need to use 
mythtv-setup to set your IP address properly on every host.  I'm 
guessing that's why you're getting this error after interrupting the 
upgrade.


> I thought of installing 0.24 on the new system and then migrating.
> But I cannot for the life of me figure out how to get Ubuntu 12.04 to 
> install Myth 0.24.
>
> Thanks!
> Eric
>
> P.S. - Once I get past this I'll be back for the latest advice on how 
> to configure VAAPI.
> I am using a small ITX system and don't want to have to put a nvidia 
> card in there if I can help it.
> Obsessed with power consumption...

You do realize that an idling GT430 would take about 7-9W, and a 
VDPAU-capable card may use significantly less power than using either 
software decode or even VAAPI decode during playback (as VDPAU does 
decode and presentation).  Therefore, adding a VDPAU-capable card may 
actually decrease overall power usage--especially if...

The /best/ way to save power is to shut down the system when not in 
use.  That extra 9W VDPAU-capable card for, say, 3hrs/day that you're 
using the system = 27Wh/day, which is less than 10kWh/yr (which is about 
$1.20 at US national average electricity price of $0.12/kWh).  Now, 
let's say that your ITX system uses (an impossible) 10W whether idling 
or at full load without that VDPAU-capable card installed.  That 10W * 
21hrs/day during which you're not using the system = 210Wh/day = 
~77kWh/yr wasted.  So, shutting down the system when not in use will 
allow you to get yourself 7 VDPAU-capable cards (actually, far more, 
since you won't have a 10W system that can run MythTV).  :)

Remember that common sense isn't a good meter for electricity usage, so 
just because adding a new component means another piece using 
electricity, doesn't mean that total electricity usage will be greater 
(and, definitely doesn't mean it will be sufficiently greater to worry 
about).  :)  Just my $0.02.

Mike


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