Exadata migration single-instance discussion

[Chris Taylor]

Our current configuration:

Source System:
- 12.1.0.2
- Not multi-tenant
- Not RAC
- 80+ TB

Target System:
- Exadata with 12.1.0.2 db_home
- Multi-tenant
- RAC

Right now we're in the early phases of brain-storming how to migrate this
DB and incur little downtime.

Here's a thought (and question) I wanted to discuss:

IF we want to use Standby and build the standby on Exadata (based on Oracle
whitepapers), here's what I was thinking:

- Build TARGET CDB and empty PDB on Exadata
- do an RMAN full backup on SOURCE system to fast NAS-attached storage
- On Exadata , use RMAN duplicate to duplicate using backup files directly
to the empty PDB ?

Basically, I'm curious how to do the RESTORE (duplicate or other) directly
into a PDB on the Exadata?

If I pre-build an empty PDB, I don't think that will work for an RMAN
duplicate - but I guess an standard RMAN restore would work?

If I don't pre-build an empty PDB, can I restore/duplicate the RMAN backup
as an PDB?

I'm a little confused on how to do the restore to a PDB I guess.

(And we were told the CDB/PDB setup is the only supported setup on Exadata)

Thanks,
Chris

[Mladen Gogala]

Hi Chris,

It is possible to clone a non-PDB database into a PDB, but with 80+ TB,
I would not do that. I would create a standby database to minimize a
downtime and then fail over to Exadata when it's time.

Post by Chris Taylor
- 12.1.0.2
- Not multi-tenant
- Not RAC
- 80+ TB
- Exadata with 12.1.0.2 db_home
- Multi-tenant
- RAC
Right now we're in the early phases of brain-storming how to migrate
this DB and incur little downtime.
IF we want to use Standby and build the standby on Exadata (based on
- Build TARGET CDB and empty PDB on Exadata
- do an RMAN full backup on SOURCE system to fast NAS-attached storage
- On Exadata , use RMAN duplicate to duplicate using backup files
directly to the empty PDB ?
Basically, I'm curious how to do the RESTORE (duplicate or other)
directly into a PDB on the Exadata?
If I pre-build an empty PDB, I don't think that will work for an RMAN
duplicate - but I guess an standard RMAN restore would work?
If I don't pre-build an empty PDB, can I restore/duplicate the RMAN
backup as an PDB?
I'm a little confused on how to do the restore to a PDB I guess.
(And we were told the CDB/PDB setup is the only supported setup on Exadata)
Thanks,
Chris

[Franck Pachot]

Hi you can not duplicate directly to a PDB but if you have a standby
non-CDB and an empty CDB you can

- Open the standby
- generate unplug .xml with dbms_pdb
- stop it
- plug (nocopy) it to the CDB
- run the noncdb_to_pdb to convert the dictionary to a PDB one

Test it to check the time (it is highly cpu intensive) but this doesn’t
touch the data to time do not depend on the size.

Regards,
Franck

Post by Mladen Gogala
Hi Chris,
It is possible to clone a non-PDB database into a PDB, but with 80+ TB, I
would not do that. I would create a standby database to minimize a downtime
and then fail over to Exadata when it's time.
- 12.1.0.2
- Not multi-tenant
- Not RAC
- 80+ TB
- Exadata with 12.1.0.2 db_home
- Multi-tenant
- RAC
Right now we're in the early phases of brain-storming how to migrate this
DB and incur little downtime.
IF we want to use Standby and build the standby on Exadata (based on
- Build TARGET CDB and empty PDB on Exadata
- do an RMAN full backup on SOURCE system to fast NAS-attached storage
- On Exadata , use RMAN duplicate to duplicate using backup files directly
to the empty PDB ?
Basically, I'm curious how to do the RESTORE (duplicate or other) directly
into a PDB on the Exadata?
If I pre-build an empty PDB, I don't think that will work for an RMAN
duplicate - but I guess an standard RMAN restore would work?
If I don't pre-build an empty PDB, can I restore/duplicate the RMAN backup
as an PDB?
I'm a little confused on how to do the restore to a PDB I guess.
(And we were told the CDB/PDB setup is the only supported setup on Exadata)
Thanks,
Chris
--
Mladen Gogala
Database Consultant
Tel: [phone]

[Andy Wattenhofer]

On Mon, Aug 13, 2018 at 1:35 PM, Chris Taylor <

Post by Chris Taylor
[...]
(And we were told the CDB/PDB setup is the only supported setup on Exadata)

I'm not sure who told you that, but I don't believe it to be true. You
could simplify your migration and save some time if you did a like-for-like
move with rman duplicate as non-CDB and save the CDB/PDB conversion for
another party.

[Chris Taylor]

Yeah, I wondered about that as well - this is Exadata Cloud at Customer so
I'm not sure if that makes any difference.

I've sent an email to our Oracle Exadata support team to get a 'final' /
'official' answer on that.

Chris

Post by Andy Wattenhofer
On Mon, Aug 13, 2018 at 1:35 PM, Chris Taylor <

Post by Chris Taylor
[...]
(And we were told the CDB/PDB setup is the only supported setup on Exadata)

I'm not sure who told you that, but I don't believe it to be true. You
could simplify your migration and save some time if you did a like-for-like
move with rman duplicate as non-CDB and save the CDB/PDB conversion for
another party.