[Fredrik Persson P (QRA)] Please read the entire mail! In the end, I'm coming
to a conclusion that
probably obsoletes a lot of the previous junk that I wrote. I've been writing
this email all day and
I've become wiser along the day too...
> >I've been assigned the task to back up an Oracle database w/ amanda. I'm
> >also told (by the db administrator) that a have to read the files under /u02
> >(a directory in the root of the file hierarchy) in a certain order.
>
> Ummm, that's very odd. I've talked with my Oracle admin and we're not
> sure what it is you're trying to do here. Could you elaborate?
>
[Fredrik Persson P (QRA)] Absolutely! Our main concern seems to be that the
database must operate 24/7. The scheme that we thought up was to run the "begin
backup" command on all tablespaces before amanda starts her work. When she's
finished, the "end backup" command is run on all tablespaces. When all the
tablespaces
are brought "back into action", the command ALTER SYSTEM SWITCH LOGFILE is
issued,
to create a new ARCHIVELOG file, even thought the old one might not be "full".
To restore the contents of the db, we first bring the tablespaces back, and
then apply
the archivelog file to them. Now, there seems to be a file called the "control
file". If this
file is backed up before the tablespaces, and the tablespaces are altered
during backup,
we cannot restore the system. The control file is out of date and we get an
error message
similar to "control file older than tablespace". Can't recall the exact words,
but that's what
it means.
So, what I want to do is to backup the tablespaces first, and the control file
after that. That's
why I need to tell amanda to do things in a certain order.
> Also, the way we back up our Oracle system is to dump it to a scratch disk
> area and then let Amanda back that up. And yes, we've done restores :-).
> And they even worked :-).
>
[Fredrik Persson P (QRA)] Are you running 24/7? If so, how do you deal with
the issue
of changes in the db during file transfer? Do you use raw partitions or does
Oracle run on top
of a file system?
> The scripts we use are at:
>
> ftp://gandalf.cc.purdue.edu/dbbackup.*
>
[Fredrik Persson P (QRA)] That link didn't work. Did you mean
ftp://gandalf.cc.purdue.edu/pub/amanda/dbbackup.*
> >Is there a way to tell Amanda this?
>
> If this really ends up being the way you need to do this, I have some
> hacks that I think would work. But let's make sure you're headed down
> the right path first.
>
[Fredrik Persson P (QRA)] After spending the day pondering this issue, I
think we've come to the conclusion that
we'll copy the db files to a temp storage, and then backup them from there as
if they were regular files.
This is your approach too. I'd say it's a good one. Minimizes db backup time
and gives us control
over the order when storing db files.
I've browsed your scripts. Are those GPL'ed or something similar? Right now,
we're using our own scripts
that can be said to be stripped versions of yours. However, I might be
interested in your stuff later.
Thanks for your help! Using a temp storage was pretty smart.
/Fredrik Persson
