[mythtv] [mythtv-commits] mythtv commit: r15933 by cpinkham

[Michael T. Dean]

On 02/15/2008 06:00 PM, Robert Kulagowski wrote:
> Nigel Pearson wrote:
>   
>> On 12/02/2008, at 11:56 PM, Michael T. Dean wrote:
>>     
>>> at least the user will have a backup they can use for
>>> http://mythtv.org/docs/mythtv-HOWTO-23.html#ss23.7 .
>>>       
>> Which reminds me, the doco needs updating to mention
>> the new auto-backup files, their storage groups, et c.
> I'll be putting something together; it was ticket 4613 that had the 
> details, right?

Robert,

Just wanted to give you an update on the database backup stuff as I just 
saw a commit to the HOWTO.

Anyway, I think we should leave the database backup documentation as it 
is for now.  I'm making some pretty major changes to the way it works, 
so any docs we create now will be obsoleted in short order (and, I think 
it will even change for 0.21 users--more on that later).

We could mention the DB Backups storage group, but it really doesn't 
apply to any 0.21 users since we only do an automatic backup when the DB 
schema version changes, which will almost definitely only happen on the 
initial upgrade--and at that time, the users won't yet have storage 
groups.  Therefore, since the automatic backup will only run a grand 
total of one time, we can leave it out of the docs for now.  And, at 
this point, I don't feel it's good to encourage the users to "assume" 
that Myth will be able to successfully backup the DB (as there are many 
ways the built-in backup can fail).

The changes I'm making are inspired by comments from Daniel K., Stuart 
M., and Rob S., who suggested a matched pair of scripts--one for backup 
and one for restore.  Distros can replace these scripts with their own.  
The scripts, however, will "abstract" out all the differences in the 
backup and restore process, so we'll be able to write HOWTO 
documentation for our scripts and it should apply to other distros even 
if they replace our scripts.

I have a backup script basically complete (doing the backup, 
compression, and rotation) and am working on the restore script.  The 
restore script will handle full restores (as in #23.5) as well as 
"partial" restores (#23.7--moving your data to a new host) as well as 
"hostname-change" restores (#23.15).  So, once these scripts are 
written, we can significantly simplify the HOWTO docs.  Both scripts 
will be usable by any MythTV user--regardless of which version of MythTV 
they're using.  And, the backup script can be used from a 
startup/shutdown script or a cron job, so it should make it much easier 
for users to get and maintain proper backups.

Though the use of those scripts for automatic backups won't be 
backported into the 0.21 branch, as mentioned, the 0.21 users really 
won't be using the automatic backup stuff, anyway.  However, I hope to 
either convince the devs to drop a copy of the scripts in the 0.21-fixes 
contrib directory or, if nothing else, link to them from the HOWTO 
documentation and encourage users to use them with their 0.21 versions.  
Therefore, I'd like to see the HOWTO updated to suggest the use of these 
scripts even for 0.21 users.

Once I finish the scripts, I will write up the HOWTO documentation for 
the database backup/restore, since it's not really your job to do so.  I 
will also include documentation on the DB Backups storage group (since 
that will be something they may want to have set before they upgrade to 
0.22).  Then, you can simply edit/fix my initial draft rather than doing 
all the work yourself.

Hope I wasn't too late in getting this info to you (and hope you haven't 
spent any time on it, yet).  I just couldn't decide what approach was 
best, so I kept flip-flopping between thinking we need to update the 
docs and wanting to wait.  I'm now hoping to wait.

Thanks,
Mike