Cloning Data Warehouse to new server

[groucho47]

My management is asking me to find the best way to migrate our 3.3 TB data warehouse to a new server. I currently use RMAN to back up the database. This is done offline on Sundays, and it takes about 9 hours, compressed backups to disk. Archived log backups are done online, not in conjuction with the db backup.

I have read a number of documents detailing step to use OEM Db Control (aka dbconsole) to clone the database to the new server.

I have a few questions:

1. I need to clone the Oracle SW first, as our current install has patches, so it should take less time. Has anyone out here done that successfully, and how?
2. Do you think just restoring from the last RMAN backup and doing recovery would be faster than cloning?
3. On the new server, I have assumed that the root user (not me) would have to pre-create the OFA structure, e.g.; we have some mount points like /f01/oracle/DBNAME or /g01/oracle/DBNAME. I cannot imagine that the Db control Gui or Rman could create that structure on the target server. Is that correct?
4. There seems to be an attitude in my shop that the storage array mount points and OFA would not have to be identical on the target server. Any opinions?

Any advice you can provide will be appreciated. Back in 1995, I successfully manually cloned a database to a new server in an HP environment, but it was only about 70G!! This is a whole new ballgame.

[PAVB]

Couple of questions...

1- How much of an outage can you get to complete the job?
2- Is the new server on the same subnet?
3- Is new server same brand/architecture as old server is?
4- Will new server run same O/S version as old server does?
5- Are you just migrating from A to B or are you also planning to upgrade/patch target system?
6- What kind of storage subsystem supports this DWH? is it a SAN?
7- What kind of storage are you using? is it cooked filesystems? raw devices? ASM?

[LKBrwn_DBA]

After answering and pondering on the excellent questions posted by PAVB, you may want to consider the following:

1. I need to clone the Oracle SW first, as our current install has patches, so it should take less time. Has anyone out here done that successfully, and how?

Check out the "Cloning an Oracle home" section in the fine Oracle® Database Installation Guide.
I posted a link to the 10g manual, but it is the same for any OS.

2. Do you think just restoring from the last RMAN backup and doing recovery would be faster than cloning?

Fast would be using latest backup and "DUPLICATING" the database.
Faster would be to set the database in backup mode, use os utilility to clone the mount points, copy the archive logs over and start the db on the other server.
Less downtime would be creating standby and then performing switch-over.

3. On the new server, I have assumed that the root user (not me) would have to pre-create the OFA structure, e.g.; we have some mount points like /f01/oracle/DBNAME or /g01/oracle/DBNAME. I cannot imagine that the Db control Gui or Rman could create that structure on the target server. Is that correct?

Correct root user must pre-create the mount points,

4. There seems to be an attitude in my shop that the storage array mount points and OFA would not have to be identical on the target server. Any opinions?

Mount points not necessarily would have to be identical on the target server, but if you are migrating a database, you should conserve same file structure unless you want to follow a better OFA scheme.

[groucho47]

Thanks for feedback. Regarding questions from PAVB:

1- How much of an outage can you get to complete the job?
They are in serious cost cutting mode here. IT management will not spend a lot of $$$ on the new server. The attitude seems to be "as quickly as we can, and if the business is not happy with a long delay, they can give us a bigger budget". They are shooting for no more than two days.

2- Is the new server on the same subnet?
Yes

3- Is new server same brand/architecture as old server is?
Yes

4- Will new server run same O/S version as old server does?
Yes

5- Are you just migrating from A to B or are you also planning to upgrade/patch target system?
Initially moving to new server, after it stabilizes we plan to upgrade to 11Gr2

6- What kind of storage subsystem supports this DWH? is it a SAN?
I only wish. We have an old Hitachi San that is past end of life, and they are too cheap to pay for support. So, you might see it soon on ebay (just kidding). Instead, our two storage arrays are a Sun 3511 and a Sun 2540. My plan is to put all the datafiles on the 2540 and the flash recovery area on the 3511. There is also a test database that uses some space on the 3511.


7- What kind of storage are you using? is it cooked filesystems? raw devices? ASM

Both arrays are using ZFS file system.

The current server is an old Sunfire 6800 that is WAY past EOL.
I think they are seriously considering a Sun M4000, but they will not tell me any more than that, because they probably think I will have a heart attack. (They may be right). I'm guessing the new server will not be able to handle some of our biggest loads and especially the Rman backups, which use 12 channels.