IDS Forum

Re: Info req "ontape -a backing up of logical logs

Posted By: Martin Fuerderer
Date: Wednesday, 14 May 2008, at 8:02 a.m.

In Response To: Info req "ontape -a backing up of logical logs" (VIKAS HIVARKAR)

Hi,

uhmm, no. It does not work like that.

I understand that you want to do repeated execution of
"ontape -a", but all the log backup data should go to the
same file.

With your onconfig setting, "ontape -a" will write to the
file /usr/informix/logicallog/logfile . But the next execution
of "ontape -a" will prompt for a new tape and after your
<RETURN> it will expect a new tape. Therefore it will
overwrite the file, rather than append to it.

Unfortunately there is no STDIO functionality for logical log
backup. This exists only for dbspace archiving. The (main)
reason is that a log can be backed up only once! So if
such a log backup would go to STDIO and 'gets lost', then
it can't be backed up again and thus is really lost.

But instead, with IDS 11.10 you can use the new functionality
"ontape backup to directory". Instead of specifying a file
name for LTAPEDEV, you specify a directory. With this
"ontape -a" will create a new file in this directory for each
logical log file backed up. It will do so regardless of how
many logical log files are backed up with one execution
of "ontape -a". The file names created will be unique (with
the unique log number as part of the file name), so there is
no danger of overwriting an earlier log backup file. Also,
if a log backup file already exists (because a log is backed
up again after a "Point In Log Restore" inbetween), then
the old file will be renamed (rather than overwritten).

Upon restore "ontape -r" or "ontape -l" will find the
necessary log backup files and restore them. (They need
to be in the directory, though.) This should make the whole
process of backup to and restore from file system much
easier. Still it is recommended to put the backup files
at some point to a more permanent (off-site) storage (e.g.
tapes), just for safety from hardware failure, flood, fire, etc.

ON-Bar is different in that a storage manager (SM) is
responsible for keeping the backup objects. There will be
one backup object in the SM for each logical log backed up.
ON-Bar will keep track of these objects in the internal
database "sysutils" and in a file "ixbar.<servernum>" in
$INFORMIXDIR/etc directory. The latter is necessary for
cold restores when the sysutils database is not on-line.
This information will be used to request and retrieve the
needed logical log backup objects from the SM during
a restore.

Whether you manually have to provide tapes to your SM
depends on the setup and configuration of the SM. If you
have only a single tape drive (or two), then you probably
have to change tapes manually. If you have a tape
library with a roboter, then it will do it, and you don't need
to do it manually.

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

IBM Deutschland Entwicklung GmbH
Chairman of the Supervisory Board: Martin Jetter
Board of Management: Herbert Kircher
Corporate Seat: Boeblingen, Germany
Reg.-Gericht: Amtsgericht Stuttgart, HRB 243294

ids-bounces@iiug.org wrote on 14.05.2008 12:21:20:

> Hello all,
> IDS -11.10.FC2W1
> Os - solaris 10
>
> we are currently using ontape -c to back up our logical logs on remote
tape.
> now we are planning to using ontape -a to backup the logs on file system
on
> the same server.
>
> pls tell me if i set the onconfig as
> LTAPEDEV /usr/informix/logicallog/logfile
> LTAPESIZE 1000000
> and run a script (shell script with all env and other parameters
setproperly)
> after every 10 minutes which will do
>
> $INFORMIXDIR/bin/onmode -l
> $INFORMIXDIR/bin/ontape -a 1>>$LOG 2>&1 <<!
> y
> !
>
> Now will ontape APPEND the logical log backup in the
> usr/informix/logicallog/logfile after ever 10 minutes or will it over
write
> the logfile .
> If it appends and the logfile now contains logical logs 320 - 520
> and now if i
> have to restore a level 0 with logical logs saying that
> Roll forward should start with log number 501
> then in this case can i simply mount the logtape on
/usr/informix/logicallog
> and will informix start the recovery starting form 501 from the tape
which
> contains 320 - 520 logs.
>
> Sorry for a basic question but want to be clear about the process.
>
> Also pls let me know if ONBAR is more preffered than ontape for backup &

> recovery ( except for the fact that it does parallel bkps of dbspaces
and so
> is faster then ontape )
> In onbar do we have to manually give log tapes to informix as i
beendoing in
> ontape (dont know any other method for ontape).
> Thanking you all in advance
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>

Messages In This Thread

• Info req "ontape -a backing up of logical logs"
  VIKAS HIVARKAR -- Wednesday, 14 May 2008, at 6:21 a.m.
  • Re: Info req "ontape -a backing up of logical logs
    Martin Fuerderer -- Wednesday, 14 May 2008, at 8:02 a.m.
    • Re: Info req "ontape -a backing up of logical logs
      VIKAS HIVARKAR -- Wednesday, 14 May 2008, at 8:39 a.m.
      • Re: Info req "ontape -a backing up of logical logs
        Martin Fuerderer -- Wednesday, 14 May 2008, at 12:21 p.m.
  • Re: Info req "ontape -a backing up of logical logs
    Art Kagel -- Wednesday, 14 May 2008, at 9:20 a.m.
    • Re: Info req "ontape -a backing up of logical logs
      VIKAS HIVARKAR -- Wednesday, 14 May 2008, at 11:18 a.m.
      • Re: Info req "ontape -a backing up of logical logs
        Martin Fuerderer -- Wednesday, 14 May 2008, at 11:57 a.m.
      • Re: Info req "ontape -a backing up of logical logs
        Keith Simmons -- Wednesday, 14 May 2008, at 12:25 p.m.
    • Re: Info req "ontape -a backing up of logical logs
      VIKAS HIVARKAR -- Thursday, 15 May 2008, at 6:25 a.m.
      • Re: Info req "ontape -a backing up of logical logs
        Art Kagel -- Thursday, 15 May 2008, at 7:11 a.m.
        • Re: Info req "ontape -a backing up of logical logs
          VIKAS HIVARKAR -- Thursday, 15 May 2008, at 8:11 a.m.
          • Re: Info req "ontape -a backing up of logical logs
            Art Kagel -- Thursday, 15 May 2008, at 9:15 a.m.
      • Re: Info req "ontape -a backing up of logical logs
        Davis Kwong -- Friday, 16 May 2008, at 4:03 p.m.
        • Re: Info req "ontape -a backing up of logical logs
          VIKAS HIVARKAR -- Monday, 19 May 2008, at 6:52 a.m.
          • Re: Info req "ontape -a backing up of logical logs
            Martin Fuerderer -- Monday, 19 May 2008, at 8:53 a.m.
            • Re: Info req "ontape -a backing up of logical logs
              VIKAS HIVARKAR -- Monday, 19 May 2008, at 9:38 a.m.
              • Re: Info req "ontape -a backing up of logical logs
                Art Kagel -- Monday, 19 May 2008, at 9:53 a.m.

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