[mythtv-users] MythTV 0.23 Available

[John Drescher]

On Tue, May 11, 2010 at 1:26 PM, Richard Shaw <hobbes1069 at gmail.com> wrote:
> On Mon, May 10, 2010 at 9:16 PM, Brian J. Murrell <brian at interlinx.bc.ca> wrote:
>> On Tue, 2010-05-11 at 11:56 +1000, Phill Edwards wrote:
>>>
>>> Before I do a major upgrade I use partimage on Sysrecue CD to take a
>>> partition image copy of my /boot and /root partitions (I don't backup
>>> the /video partition). So then if anything goes wrong I can restore
>>> easily (and I have done on quite a few occasions!).
>>
>> Yeah.  What he said.  But really, dude, look into LVM and snapshots.
>> Way easier to manage and do.  No copying and waiting.  Just snapshot and
>> upgrade.
>
> I'm trying to understand how this would work. If we were talking about
> something like Virtualbox I would understand. The snapshot seems to
> track changes without modifying the original disk image so if you run
> into a problem you delete the snapshot and you're back to your
> pre-upgrade condition.
>
> As far as I can tell, LVM snapshots work differently. The underlying
> file system continues to be modified but it copies the to be modified
> chucks to the snapshot first to present an unmodified file system.
>
> Other than letting you make a live backup (such as dd'ing the who
> volume) I don't see any real advantage. You still need enough space
> somewhere to make a complete copy. If you run into an issue, how
> exactly does this help you?
>

I believe you only need space for the parts of the filesystem that
have changed not the entire filesystem.

John