Re: Minimizing backup induced downtime

Steve Howard <stevedhoward_at_gmail.com> wrote:
> On Jul 12, 7:33 am, Alexander Skwar <alexan..._at_skwar.name> wrote:

>> In such a scenario/setup, wouldn't RMAN make the downtime larger? Or am
>> I overlooking something completely (which might of course be true)? Hm,
>> right now, I'm pretty much thinking, that a shell script based backup
>> (as I'm currently doing) is a better approach, don't you think?

>
> Just take an export...LOL!

*LOL* You know, actually I AM doing an export. But that's just for the sake of completeness and also because it's so easy and doesn't cost anything. I'm doing that, so that it's easy to IMP all the data from this database to some other database. As you might want to recall, I'm talking about tiny databases (17g) with just even much more tiny exports (700m).

> RMAN is the way to go.

That's why I'm trying to make use of RMAN.

> You don't need to have anything down,

I don't? How do I ensure, that my application doesn't mess with data that's not under the control of Oracle? My primary concern is, that a user can delete/modify (and add, but I don't care much about this) files stored on the filesystem, while RMAN is running. Because of this, the combination of database + vault (see response to Davids post) might not be consistent. That's something, which I'd pretty much like to avoid, if possible. And it IS possible, when I shut down "everything" (ie. app + oracle). I don't yet see, how this is possible, when I not stop at least the application.

But how do I *ensure* that the application is in a consistent state, without shutting it down? The application doesn't have a "backup mode", where it writes all pending tasks, or something like this. If you're interested, the application is "Teamcenter Enterprise" by EDS/UGS/Siemens.

> you can
> take incremental backups that can be much faster than anything else
> you have noted,

Actually, the actual time it takes to do the "backup" (ie. writing to tape) doesn't matter much at all to me. Reason: I'm taking a backup of my snapshot. During this time, the application is up again and users can work with it, just like usual. A backup can't get much faster than that - from a users perspective, the downtime because of backups is about 10 seconds up to a minute. Even an incremental backup will take longer.

> and it is probably (at some point) all Oracle will
> support going forward.

Uhm. Think so? Don't you think, that they'll always support cold backups, ie. backups when the database has been shut down?

> It's an incredibly powerful technology.

No doubt. I just need to find a way, to make it work for me. I suppose that this WILL be possible. I just don't know how - *yet*. :)

Thanks a lot for your response as well,

Alexander Skwar Received on Thu Jul 12 2007 - 09:23:19 CDT