Use of Flashcopy with GDPS/PPRC

David Lam

Use of Flashcopy with GDPS/PPRC
Hi fellow DB2-L subscribers,

I have a question regarding the use of Flashcopy with GDPS/PPRC.

We would like to be able to use Flashcopy when running DB2 CHECK utility SHRLEVEL CHANGE on large tablespaces to reduce time of copying database files, during which the database object is put in read only access. Our shop is also planning to introduce GDPS/PPRC soon at the same site. My storage administrator has raised concern about using Flashcopy with GDPS. According to GDPS documentation, using Flashcopy with the target being a PPRC primary volume may cause mirroring to break and IBM has warnings against using it under GDPS with DB2.

That said, I have seen postings that mention shops running PPRC and use Flashcopy. Is there shop out there that use Flashcopy with the target being a PPRC primary volume? Would you be willing to share with us your experience and how you manage to preserve mirroring?

Thanks in advance!
and Happy holidays
David Lam

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Daniel Luksetich

Re: Use of Flashcopy with GDPS/PPRC
(in response to David Lam)
How extraordinarily interesting. I don't know of anyone who has deployed
GDPS/PPRC with success, and I have witnessed two failed tests of this
technology. Most I know of use XRC.

That besides I'm interested to know why you would take a flash copy of the
primary vol and not the secondary? In addition I'm extremely interested to
know how you would time correct the flash copies.

Thanks,
Dan

On Thu, 16 Dec 2010 11:06:38 -0500, David Lam <[login to unmask email]> wrote:
> Hi fellow DB2-L subscribers,
>
> I have a question regarding the use of Flashcopy with GDPS/PPRC.
>
> We would like to be able to use Flashcopy when running DB2 CHECK utility
> SHRLEVEL CHANGE on large tablespaces to reduce time of copying database
> files, during which the database object is put in read only access. Our
> shop is also planning to introduce GDPS/PPRC soon at the same site. My
> storage administrator has raised concern about using Flashcopy with
GDPS.
> According to GDPS documentation, using Flashcopy with the target being a
> PPRC primary volume may cause mirroring to break and IBM has warnings
> against using it under GDPS with DB2.
>
> That said, I have seen postings that mention shops running PPRC and use
> Flashcopy. Is there shop out there that use Flashcopy with the target
being
> a PPRC primary volume? Would you be willing to share with us your
> experience and how you manage to preserve mirroring?
>
> Thanks in advance!
> and Happy holidays
> David Lam
>
> _____________________________________________________________________
> * IDUG EMEA * Prague, Czech Republic * 14-18 November 2011 *
> http://IDUG.ORG/EMEA *
> * If you are going to attend only one conference this year, this is
it!
> *
> _____________________________________________________________________
> http://www.IDUG.org/mentor
> Mentoring should be a rewarding experience for everyone...
> IDUG is offering up to 80% off when you both come to the conference!
> _____________________________________________________________________
>
> If you need to change settings, http://www.idug.org/cgi-bin/wa?A0=DB2-L
is
> the home of IDUG's Listserv

_____________________________________________________________________
* IDUG EMEA * Prague, Czech Republic * 14-18 November 2011 * http://IDUG.ORG/EMEA *
* If you are going to attend only one conference this year, this is it! *
_____________________________________________________________________
http://www.IDUG.org/mentor
Mentoring should be a rewarding experience for everyone...
IDUG is offering up to 80% off when you both come to the conference!
_____________________________________________________________________

If you need to change settings, http://www.idug.org/cgi-bin/wa?A0=DB2-L is the home of IDUG's Listserv

David Lam

Re: Use of Flashcopy with GDPS/PPRC
(in response to Daniel Luksetich)
Hi Dan,

Thanks for responding to my email.

I should clarify that we are not trying to use Flashcopy for backup. We want to use it for the Check utility. When run with SHRLEVEL CHANGE, the DB2 Check Utility can use Flashcopy to copy DB2 objects to shadow datasets. For large objects, Flashcopy should be faster, thus reduce the time the objects spent in UTRO. The part I mention about the target being a PPRC primary volume, perhaps I should have said "the destination storage volume is on a PPRC primary device".

The recent edition (Dec 2010) of the DB2 utility Guide I just read provided more info about Flashcopy than the older one I was reading. There are 2 new ZPARMs to manage/influence the FCTOPPRCP setting. I was also reminded of the ZPARM UTIL_TEMP_STORCLAS that we can use to direct the shadow dataset's destination to storage volumes on non-mirrored devices.

Have a good weekend.
David

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