IDS Forum

Re: Configuring ISM/OnBar to backup to disk

Posted By: Martin Fuerderer
Date: Thursday, 2 June 2005, at 10:10 a.m.

In Response To: Configuring ISM/OnBar to backup to disk (Peter J Diaz de Leon )

Hi,

generally this is done with "expiration".
Now I have never actually done this with disk files.
(My cycles during development and testing are too short and
I usually initialize the whole thing from scratch rather than
bother with expiration ...)

But I assume that you want to keep the stuff on tape
longer than on disk, right ?
The question then is, how do you want to restore something
where the file has been expired already and you have restored
the file from tape "using external software" ?

ISM (as other storage managers) keeps information about
the backup media and the objects contained on this media
in some kind of "internal database". When you expire the
media, then (eventually) ISM will also get rid of that
information as it is not needed anymore. Now after some
time (meanwhile ISM has "forgotten" about that old stuff)
you put that expired media back (via "restore using external
software"). I doubt that ISM will be able to find backed up
objects on this media so easily. I.e. I doubt that you could
restore a dbspace or log from such a thing just like that.

Maybe you can let ISM "scan" that old, restored file media,
so that it can again build the information about the media and
the stuff contained on it, or you have to also backup that ISM
internal information in the first place when you "backup
using external software" (to then be able to restore it as well).

There also is a concept of "cloning" backup objects. I have
never looked into this functionality in much detail, but I know
that you can e.g. clone a backup object so that it is on disk
media and on tape media. But I don't know whether you
then can expire one of them (i.e. the disk media) without
expiring the other (i.e. tape media). You may want to look
into this in more detail ... ?
As this cloning is done by ISM (or Legato Networker) means
(rather than "external software), ISM will be aware of what
happened and where the stuff can be found. That way I would
have more confidence in being able to restore from the clone
(instead of from something "restored by external software").

Expiration at ON-Bar level is done using "onsmsync" utility.
Check "IBM Informix Backup and Restore Guide" manual.
For ISM specific stuff, please see "IBM Informix Storage
Manager Administrator's Guide" manual.

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

forum.subscriber@iiug.org wrote on 06/02/2005 01:39:26 PM:
> Running IDS 9.40.UC6 on RH 3.0 ES and I have ISM configured to backup
> the database and the logs to disk.
> We will be using external software to back up this files nightly. How
> do I configure ISM to over write the previously
> written files?
>
> Back when we were using tape drives I would set up the devices as "auto
> managed" and "auto recycle" and cycled the tapes
> every 14 days. So on day 15 tape 1 was relabeled and rewritten.
>
> It appears I don't have that option when using files, how do I do it?
>
> Thanks
> Peter

Messages In This Thread

• Configuring ISM/OnBar to backup to disk
  Peter J Diaz de Leon -- Thursday, 2 June 2005, at 7:39 a.m.
  • RE: Configuring ISM/OnBar to backup to disk
    malcolm weallans -- Thursday, 2 June 2005, at 9:59 a.m.
  • Re: Configuring ISM/OnBar to backup to disk
    Martin Fuerderer -- Thursday, 2 June 2005, at 10:10 a.m.

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