[mythtv-users] Changing from 0.21 to 0.25 using new hardware
Michael T. Dean
mtdean at thirdcontact.com
Fri Jun 1 15:31:24 UTC 2012
On 06/01/2012 01:02 AM, Bob Long wrote:
> Digging up an old thread:
>> On Wed, Mar 14, 2012 at 5:40 PM, Bob Long wrote:
>>> I currently have a reliable 0.21 system (combined FE/BE) running on
>>> Ubuntu 8.04. However, it has some hardware limitations (AGP slot, so
>>> able to install PCI-e video for high definition/VDPAU; motherboard does
>>> not accept modern larger capacity hard drives; a couple of other
>>> so I'm looking to build a new combined FE/BE with new hardware.
>>> I've done some tests with new hardware with 0.24 and that seems fine.
>>> However, would it be better to me to wait for 0.25 to build the real
>>> system? That is, will it be better/easier to build a 0.25 system from
>>> scratch rather than try to upgrade from 0.24? There's no rush for the
>>> new system, so I can wait if it's better/simpler/more future-proof.
>>> And would it also be better to wait for Ubuntu 12.04, rather than use
>>> 11.10? Is upgrading from 11.10 to 12.04 likely to break things?
>>> Then, with whatever flavour of new system I have built, how to get
>>> recordings/schedules etc from the 0.21 system?
>>> http://www.mythtv.org/wiki/Release_Notes_-_0.25 says it won't upgrade
>>> from before 0.22. But I don't want to try any upgrade on the existing
>>> system anyway - I want to keep it running as is.
>>> I've read http://www.mythtv.org/wiki/Database_Backup_and_Restore but
>>> don't really understand if that is applicable in this case. That warns
>>> about doing partial restores, but would that process do a full restore
>>> of a 0.21 backup anyway? If it did, and as there will be different
>>> tuners/channels, etc, would that restore wipe out or break what had
>>> newly configured?
>>> Any pointers, or have I just not read things well enough?
> Nick replied:
>> Back up your database using the backup and restore functionality as
>> described in the wiki.
> Ok. So that will be on the old 0.21 system.
Right. (And the backup script will work on any version of MythTV, even
though it wasn't distributed with 0.21. You can download it and use it
as described at http://www.mythtv.org/wiki/Database_Backup_and_Restore
--basically the first 2 sections "Script-based Database Backup and
Restore" for a general overview and "Quick Start".)
>> Install 10.04 (LTS) and use mythbuntu-repos to get to 0.24-fixes.Give
>> it the same hostname as your old backend, or be prepared to do the
>> change of hostname thing as described in the wiki. Do not configure
>> it (ie don't bother with mythtv setup) as you will throw away that
> And that will be on the new hardware, I presume?
On either. 0.24-fixes is just a stop along the way to the goal.
>> Remove the default database and restore the one you backed
>> up, again as described in the wiki article. The database will get
>> updated to 0.24 format when the backend starts, and some will get
>> updated when the frontend starts.
> Using this?
> mythconverg_restore.pl --drop_database --create_database --filename
> Presumably that will be a full restore;
Yes. You should /always/ do a full restore--there's no benefit to a
partial restore, and if you do one, you have to reconfigure /everything/
(not just tuners and channels, but /everything/, including all settings
for backend, frontends, and all plugins). It's hours of work to
reconfigure and at the end--*if* you did everything right--you end up
with exactly what you would have had with a full restore.
> but as the new system will have entirely different tuners (different
> brands and numbers of them), different tv_grab routine, probably
> different channel IDs, will that be adding stuff I then have to get
> rid of?
Which can be completely "reset" by simply going into mythtv-setup and
doing a "Delete all video sources" and "Delete all capture cards" (not
"Delete all capture cards on <hostname>"). Then just configure tuners
and channels as if you were doing it from a clean/new database.
>> Then carry on as before until 12.04 (again LTS) is released. Back up
>> your database, then try an LTS to LTS upgrade. If that works, you are
>> sweet. If it doesn't (yes canonical I am talking to you) then do a
>> fresh install of 12.04 and use the backup you made.
>> I am assuming you can separate out all your media (recordings, video,
>> music etc) so that there is no risks of updates screwing it.
> There won't be any media to transfer.
> All I really want (I think) is to keep the "oldrecorded" to avoid
> recording what has been recorded, and "record" (?) - the shows I
> already have scheduled.
> Is that what a partial store is meant to do (I know there are warnings
> about doing only a partial restore)?
No. A partial restore is meant to allow someone who has messed with
their database--breaking the schema or corrupting the data--to try to
recover some critical non-re-creatable data into a known-good schema,
hoping to get rid of the bad stuff, while also throwing away a lot of
other good/important stuff. It's really a second-to-last-resort, with
bad side effects and a requirement to completely reconfigure all of
MythTV from scratch (and a /very/ high likelihood of creating
problems). (Where the last resort is to throw everything away and start
a new database from scratch, without any history.)
> So if I were to build 12.04 with 0.25 from scratch, completely
> configure the backend's tuners/channels/etc to make sure it all works,
> there is no way to get just that old information in (old
> recorded+schedules) without going through an intermediate 0.24 build?
No. There's no way to do a restore (partial or otherwise) into a
wrong-schema-version database. So, since 0.25 can't upgrade a 0.21
database schema, you'll need to do an intermediate upgrade to a DB
schema version that 0.25 can handle.
We dropped support for upgrading from "ancient" versions of MythTV
primarily because the major post-0.21 changes to the database work very
differently, now, due to changes to both Qt and MySQL, than they did
when the code was developed. Therefore, we can't guarantee successful
upgrades from 0.21 with modern Qt and MySQL. That said, if you use
/current/ 0.24-fixes (by which I mean you need to update the version
that ships with any mythbuntu install to current 0.24-fixes--see
http://www.mythbuntu.org/repos ), things should work well, now, with the
Qt and MySQL versions you'll have. However, if you wait longer, there's
a good chance that won't be the case. So now is definitely the right
time to do this upgrade.
Good luck, and please ask if you have any questions or encounter any issues.
More information about the mythtv-users