Steven,

As others have suggested, the best method to protect your server from loss
of data is to implement a strategy to backup your storage pools to a copy
pool on a daily basis.  One thing that I did not see mentioned is the
potential performance impact on nightly backup when migration (to tape) runs
concurrently with the nightly backups.  The impact can be significant,
especially on "busy" machine.  I normally implement an administrative
schedule to migrate all the data on disk pools to tape on a daily basis.
You can do this by setting the hi threshold of the disk storage pool to 0:

        update stg STORAGEPOOLNAME hi=0 lo=0

You will also need to setup a schedule to reset the parameters to their
normal values after the disk has been cleared:

        update stg STORAGEPOOLNAME hi=80 lo=50

If you also choose to implement a schedule to backup the disk storage
pool(s) on a daily basis, you should schedule it to run before you clear
your disk storage pools to minimize tape mounts.  Implementing both of these
strategies should provide you with better data protection and performance.

DanC
=============================================
Daniel G. Crouse
IBM Certified Specialist - ADSM
Mainstar Software Corporation
Storage and Recovery Solutions
  URL:  <www.mainstar.com>
Email:  Dan.Crouse AT mainstar DOT com <mailto:Dan.Crouse AT Mainstar DOT com>
Vmail:  800-233-6838
Voice:  404-714-5754
   Fax:  770-682-7739
=============================================

> > -----Original Message-----
> > From:       Steven McNicholas [SMTP:ste_mc AT ZDNETMAIL DOT COM]
> > Sent:       Friday, November 20, 1998 8:52 AM
> > To: ADSM-L AT VM.MARIST DOT EDU
> > Subject:    A question about migration
> >
> > Hi,
> >
> > In the company I am working for their adsm system is used in the
following
> > way....
> >
> > 1) aix clients are backup up to disk pools
> > 2) These disk pools have migration thresholds of
> > low=0% high  %
> > 3) If the high is reached then it is migrated to a tape pool.
> >
> > My question is this :
> >
> > If during the daily backup this high threshold is not met on some of the
> > disk pools,then this means that there is a whole load of client data
> > residing on (in our case)  1 disk.
> > If that disk pops then goodbye data ( could be maybe 3 days worth ?)
> >
> > What is the solution to this ?
> >
> > Is it possible to mirror the disk pools aix logical volume  to another
> > disk using aix ? or is this not possible because there are adsm disk
pools
> > in the lv ?.
> >
> > Would it just be better to lower the high migrate threshold to a very
low
> > value ?
> >
> > There is no disaster recovery as yet for this machine (no offsite
backups
> > etc ) but in the meantime I still do not want to end up losing any data
> > due to disk failures etc.
> >
> > Please help.
> >
> >
> >
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