Re: Duplex Archive Logs

Dennis Flinn <dflinn_at_eastman.com> wrote in message news:37CE087F.66982368_at_eastman.com...
> I was wondering if anyone has worked with duplexed archive logs. In
> reading the documentation about the parameters it appears that you have
> to set two parameters in the init.ora. First, the
> log_archive_duplex_dest, I then left the log_archive_min_succed_dest set
>
> to the default of '1'. After I recycled the database I forced a log
> switch and found the archive log was not written into the duplex
> location. I haven't done any further testing but after reading the
> documentation again it stated that if log_archive_min_succed_dest is set
>
> to '1' then the write to log_archive_duplex_dest is a "best effort".
> I'm not sure what that means. Like I said I haven't had the chance to
> set the log_archive_min_succed_dest to '2'. But does "best effort" mean
>
> if the server can write to log_arch_dest then if will not write to
> log_arch_duplex_dest? I guess that brings up another question. If I
> setup a duplex_dest and leave min_succed set to '1' - if the
> log_arch_dest fills up will the archive logs then switch over to
> duplex_dest with the database hanging?

We only use log_arch_duplex_dest in our init files and it works ok.

From the Backup & Recovery Guide:

Duplexing the Archived Redo Log
It is possible to write out two copies of an online redo log group to archive. Many sites may choose to do this in order to further protect the archived redo log against media failure.

The parameter LOG_ARCHIVE_DUPLEX_DEST determines the second location. Any time a redo log file is archived, it will be archived to both LOG_ARCHIVE_DEST and LOG_ARCHIVE_DUPLEX_DEST.

If set, the parameter LOG_ARCHIVE_MIN_SUCCEED_DEST determines the number of archive log destinations that a redo log group must be successfully archived to. For additional information see the Oracle8 Reference.

So, you don't have to set LOG_ARCHIVE_MIN_SUCCEED_DEST - but if you do, in your case it must be set to 2 (when you had it set to one it succeeded in writing to one - so that's OK)

Alex Received on Thu Sep 02 1999 - 05:08:05 CDT