Re: RMAN Clarification

On Aug 15, 9:27 am, Mtek <m..._at_mtekusa.com> wrote:
> Hi,
>
> We are configuring RMAN.  We are going to include the archive logs as
> part of the backup set.  Once backed up, I assume we do not need those
> logs on disk anymore.
>
> According to the documentation, if you use the option DELETE ALL
> INPUT, it will delete ALL the archive logs.  But it says if you use
> DELETE INPUT, it only delete the logs it backed up.
>
> Now, if you multiplex the archive logs, how do you know where RMAN
> took them from?

Try it, and look at the rman logs. It is sometimes a bit unexpected what it does when you try to have some redundancy, which makes one examine the assumptions one makes. For example, what I tripped over going from rman scripts I wrote myself to those custom generated by EM, was assuming that one full backup was one backup - so I was getting less controlfile backups than I expected.

Personally, I like some redundancy in archive logs, leaving them on disk for some period of time and having them in several backups has saved my backside on a number of occasions, and sometimes simply made things easier. Seeing things like:

skipping archive log file /oradata/flash/[obscured]/archivelog/ 2008_08_14/o1_mf_1_10168_4b7z2m64_.arc; already backed on 14-AUG-08

 ll /oradata/flash/[obscured]/archivelog/2008_08_14/ o1_mf_1_10168_4b7z2m64_.arc
-rw-r----- 1 oracle oinstall 1784832 Aug 14 02:35 /oradata/ flash/[obscured]/archivelog/2008_08_14/o1_mf_1_10168_4b7z2m64_.arc

kind of makes me want to slap rman up side the head. Backups run at 2:00 AM and take 35 minutes and 38 seconds, so that would be one generated at the very end of previous nights backup - but there is supposed to be:

RMAN> show retention policy;

RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 2; RMAN> show archivelog deletion policy;

RMAN configuration parameters are:
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default

And the docs say:

NONE - enables flash recovery area to delete archivelogs that are backed up to tertiary device and that are obsolete based on the configured backup retention policy. This is the default configuration.

When you have a command file like:

$rman_script="backup device type disk filesperset = 4 tag '%TAG' database;
backup device type disk filesperset = 4 tag '%TAG' archivelog all not backed up;
allocate channel for maintenance type disk; delete noprompt obsolete device type disk; release channel;
";

Seems that redundancy is overridden by the "all not backed up." So I need to slap myself. My forehead is getting very red.

jg

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