Very Computer

> I do customer support for a software company. Our product works on top of
> Oracle and DB2 databases. We have customers that want to run disk
> defragmentation on their servers, but I'm been reluctant to agree to let
> them on the assumption that the defragmentation may corrupt the DB2 database
> they are running.

> I only have about 6 months experience with DB2 and have barely scratched the
> surface of what there is to know, no doubt. I'm thinking that if it can be
> done at all, it should be done when the database is shutdown and no
> transactions are running. But the customer runs 24/7 (a *), so they
> really don't have the option of taking the database down for more than a few
> minutes at a time.

> Any experts on this newsgroup have any thought about this issue?

> Thanks in advance,

>>>Oracle and DB2 databases. We have customers that want to run disk
>>>defragmentation on their servers, but I'm been reluctant to agree to let
>>>them on the assumption that the defragmentation may corrupt the DB2
>>>database they are running.

>>If the tables are not that big, i would reorganize tables instead of
>>defrag at the disk level. In fact if you do, you may wind up with
>>worse performance than before.

> We're already doing that, but the customers are complaining about the disk
> fragmentation. I'm not convinced it's that big of a deal, but they seem to
> think so.

> >>>Oracle and DB2 databases. We have customers that want to run disk
> >>>defragmentation on their servers, but I'm been reluctant to agree to let
> >>>them on the assumption that the defragmentation may corrupt the DB2
> >>>database they are running.

> >>If the tables are not that big, i would reorganize tables instead of
> >>defrag at the disk level. In fact if you do, you may wind up with
> >>worse performance than before.

> > We're already doing that, but the customers are complaining about the disk
> > fragmentation. I'm not convinced it's that big of a deal, but they seem to
> > think so.

> Do they have other data on the disks where the DB2 data is allocated?  If
> not, why worry about defragging?

> Do they have performance problems, or are the customers just being anal?

> With DMS you only need to defrag ocassionally (when you change the
> containers), with SMS you need to defrag more often. This is one of the
> advantages of DMS.

> Defrag is for the physical files. REORG is for the internal layout inside of
> those files. You need to REORG. If your files are not badly fragmented,
> REORG will typically bring the most.

> You mention 24x7. You'll need DB2 8.1 for online reorgs.

> > I do customer support for a software company. Our product works on top of
> > Oracle and DB2 databases. We have customers that want to run disk
> > defragmentation on their servers, but I'm been reluctant to agree to let
> > them on the assumption that the defragmentation may corrupt the DB2
>  database
> > they are running.

> > I only have about 6 months experience with DB2 and have barely scratched
>  the
> > surface of what there is to know, no doubt. I'm thinking that if it can be
> > done at all, it should be done when the database is shutdown and no
> > transactions are running. But the customer runs 24/7 (a *), so they
> > really don't have the option of taking the database down for more than a
>  few
> > minutes at a time.

> > Any experts on this newsgroup have any thought about this issue?

> > Thanks in advance,

> > Les

> > With DMS you only need to defrag ocassionally (when you change the
> > containers), with SMS you need to defrag more often. This is one of the
> > advantages of DMS.

> > Defrag is for the physical files. REORG is for the internal layout
inside of
> > those files. You need to REORG. If your files are not badly fragmented,
> > REORG will typically bring the most.

> > You mention 24x7. You'll need DB2 8.1 for online reorgs.

> Mark,

> Thanks for the info.

> I'm definitely going to test this thoroughly before I have the
> customer try it, but it's good to know that it can be done. Now I just
> need to figure out if it's really needed. ;-)

> We already do a REORG (either with DB2's commands or using
> QuestCentral), so I don't think they are too bad off performance-wise.

> Being a * in a very rural area, they can get away with being down
> for short periods of time during the wee hours of the early morning,
> so they usually do a reorg on selected tables on a regular basis.
> Don't know when they can go to DB2 8.1; offically our product doesn't
> work with DB2 8.1 yet.

> Thanks again!

> Les

> > > Can you run disk defrag on Windows 2000 without damaging the DB2
files?

> > > I do customer support for a software company. Our product works on top
of
> > > Oracle and DB2 databases. We have customers that want to run disk
> > > defragmentation on their servers, but I'm been reluctant to agree to
let
> > > them on the assumption that the defragmentation may corrupt the DB2
> >  database
> > > they are running.

> > > I only have about 6 months experience with DB2 and have barely
scratched
> >  the
> > > surface of what there is to know, no doubt. I'm thinking that if it
can be
> > > done at all, it should be done when the database is shutdown and no
> > > transactions are running. But the customer runs 24/7 (a *), so
they
> > > really don't have the option of taking the database down for more than
a
> >  few
> > > minutes at a time.

> > > Any experts on this newsgroup have any thought about this issue?

> > > Thanks in advance,

> > > Les