Re: Cron management...
Date: Thu, 23 Apr 2015 10:27:47 -0400
Message-ID: <CA+fnDAZdAjT-haVUkhT7Q62W+4ufsWzCERAt2qLYreYoAp9Ofg_at_mail.gmail.com>
For the benefit of others on the list, so we don't perpetuate a completely incorrect understanding of how Oracle databases work...
On Wed, Apr 22, 2015 at 6:38 PM, Mladen Gogala
<dmarc-noreply_at_freelists.org> wrote:
> MML library is mapped into the rman address space
> sbtinit routine is executed to initialize the MML side of the channel.
>
> After that, when a "backup" command is issued, Oracle process reads the
> database and delivers the data to the channel, possibly using Oracle*Net.
The Oracle database process cannot deliver data to the rman channel using Oracle*Net - this is completely incorrect.
> The "rman" executable is a client, similar to sqlplus,
> which executes the internal functions, built into the Oracle executable
> itself and delivers the data to the destination using the channels.
This is also exactly wrong. Also this is specifically the misunderstanding that Hans was trying to correct.
> if there is a centralized node used to backup all the
> database by establishing remote connection to the database and opening
> channel toward backup software
The channel cannot be established on a remote server which has a remote connection to the database. The channel can *only* be established on the database server itself.
When you run "rman" on a remote server, the rman binary is nothing more than a remote control. Just like you push buttons on your remote to control your television, rman simply sends commands to the "remote" oracle binaries and they do all the work - including opening channels that connect to a media server.
As a comparison, this is exactly the same architecture as "data pump" imports and exports. Some of you might remember the old traditional imports and exports -- those imp/exp binaries were actually clients which shipped data over the network. The big deal about data pump was that - like rman - the expdp binary is just a remote control and the server binaries themselves do all the real work. This is also why - unlike traditional export - when you run data pump exports remotely, the dump files are always still created on the database server itself.
On Sun, Apr 12, 2015 at 8:01 PM, Seth Miller <sethmiller.sm_at_gmail.com> wrote:
> Modify your rman scripts to use an Oracle wallet to authenticate to the
> databases remotely through an rman client. That way, you can take a backup
> without having to be on the server and won't expose the password of a
> privileged account. I would also suggest creating a separate sysdba account
> just for the use of logging in to do the backups.
For the sake of anyone who's still reading this thread (if anyone is), this is the actual text of Seth's original suggestion, which seemed to cause the present superfluous and misleading discussion.
Seth specifically was showing how to:
1) "use an Oracle wallet to authenticate to the databases remotely"
2) for "logging in to do the backups"
So clearly Seth was saying that the backups would actually run on the source database server which he's "logging in to" from his remote machine. The suggestion to "save on licensing by having a special client which would connect to the databases and run backup from client" originated with elsewhere in the thread, and not from Seth.
-Jeremy
-- http://about.me/jeremy_schneider -- http://www.freelists.org/webpage/oracle-lReceived on Thu Apr 23 2015 - 16:27:47 CEST