IDS Forum

Re: Query :- Parallel ontape for logical logs

Posted By: Martin Fuerderer
Date: Monday, 5 January 2009, at 11:43 a.m.

In Response To: Re: Query :- Parallel ontape for logical logs (Art Kagel)

Hi,

having ontape (11.50) configured for log backup to directory,
when one log backup is already active (backing up several
log files in a row), starting a second log backup ("ontape -a")
yields

Performing automatic backup of logical logs.

Logbackup failed - A Log backup is already in progress.

Program over.

and exits. I.e. this does not wait for the running ontape log
backup to finish.

There is a check in the server that allows only one active
log backup operation at a time. This is independent of
the ALARMPROGRAM mechanism. Whenever a log
file is complete, the ALARMPROGRAM will be triggered
by the server, no matter whether a log backup is already
active or not. After all the server doesn't know, what was
programmed in the ALARMPROGRAM (usually it is a
shell script that can be edited by the admin).

If the ALARMPROGRAM is starting a log backup
(ontape or onbar), then this log backup will contact
the server. At this time the server checks whether
there is a log backup active already, and if so it will
issue the above error to the new log backup request.

If you do not see the above error message from an ontape
that is started while there is an active log backup already
running, then this may be due to the fact that the error
message is written to standard error (whereas the other
2 messages are written to standard out). Capturing
(in the ALARMPROGRAM where ontape is started) both,
standard out and standard error to the same file should
show the error message as well.

Regards, Martin
--
Martin Fuerderer
IBM Informix Development Munich, Germany
Information Management

IBM Deutschland Research & Development GmbH
Chairman of the Supervisory Board: Martin Jetter
Board of Management: Erich Baier
Corporate Seat: Boeblingen, Germany
Reg.-Gericht: Amtsgericht Stuttgart, HRB 243294

ids-bounces@iiug.org wrote on 02.01.2009 12:56:48:

> Ontape does not check. However, if ontape is already running the new
> iteration will wait for the first one to complete before starting. The
> danger before the 'to directory' option was available is that the new
one
> will wipe the archive file before the script running the previous
iteration
> can rename the file. Therefore one had to write the alarmprogram scripts

> very carefully to prevent a new iteration of ontape from starting until
the
> previous iteration's script had finished renaming the archive file and
> exited. Or better yet, don't run ontape at all if there was a previous
> alarmprogram script still running (that's the way I always handled it).
IB
> that with the archive to directory feature enabled this isn't a problem
any
> longer, but I'd check that with IBM before I relied on that - or better
yet:
> don't rely on it at all and still code the script carefully.
>
> Art
>
> On Fri, Jan 2, 2009 at 4:20 AM, VIKAS HIVARKAR
> <vikas.hivarkar@gmail.com>wrote:
>
> > Hello,
> > Wish you all a very happy new year !
> >
> > IDS 11.10.FC2W4, Solaris 10
> > Logical log backup using ontape to directory feature running from
> > alarmprogram.sh
> >
> > I learned from my one of my previous query threads that
> >
> > --On a busy system one execution of "ontape -a -d"
> > may backup more than one log file, especially
> > when the next log file gets full while the last one is
> > backed up. At the end of a log backup ontape
> > checks if there are (meanwhile) more logs to
> > backup. If so it just continues to backup logs.
> > Finally (when ontape caught up or log filling
> > slowed down), there will no full log to be backed
> > up when ontape finished the last one, and then
> > it will exit.--
> >
> > Now if one "ontape -a -d" is running and backing up more than
> > one logical log & also checking if any other log
> > is on verge of filling up so that it can also be backedup.
> >
> > Does ontape runs for every logical log completion (event 23)from
> > alarmprogram.sh ?
> >
> > Following is part of o/p that i capture for ontape running from
> > alarmprogram.sh
> >
> > Performing automatic backup of logical logs.
> >
> > Do you want to back up the current logical log? (y/n) n
> >
> > Program over.
> >
> > Performing automatic backup of logical logs.
> >
> > Do you want to back up the current logical log? (y/n) n
> >
> > Program over.
> >
> > I can see this many times when the previous ontape is backed up more
than
> > one
> > file.
> >
> > Does IDS check for any "ontape -a -d" running before starting a
another
> > "ontape -a -d" ?
> > should'nt it?
> >
> > Thanks
> > Vikas
> >
> >
> >
> >
>
*******************************************************************************
> > Forum Note: Use "Reply" to post a response in the discussion forum.
> >
> >
>
> --
> Art S. Kagel
> Oninit (www.oninit.com)
> IIUG Board of Directors (art@iiug.org)
>
> Disclaimer: Please keep in mind that my own opinions are my own opinions
and
> do not reflect on my employer, Oninit, the IIUG, nor any other
organization
> with which I am associated either explicitly or implicitly. Neither do
> those opinions reflect those of other individuals affiliated with any
entity
> with which I am affiliated nor those of the entities themselves.
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>

Messages In This Thread

• Query :- Parallel ontape for logical logs
  VIKAS HIVARKAR -- Friday, 2 January 2009, at 4:20 a.m.
  • Re: Query :- Parallel ontape for logical logs
    Art Kagel -- Friday, 2 January 2009, at 6:56 a.m.
    • Re: Query :- Parallel ontape for logical logs
      Martin Fuerderer -- Monday, 5 January 2009, at 11:43 a.m.

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