RE: RAC servers as-is move to new DataCenter

  • From: "Mark W. Farnham" <mwf@xxxxxxxx>
  • To: <sanjeevorcle@xxxxxxxxx>, "'ORACLE-L'" <oracle-l@xxxxxxxxxxxxx>
  • Date: Thu, 19 Mar 2015 14:23:19 -0400

Since you’re already proposing a single temporary server, why don’t you just do 
a standby on that. You don’t need horsepower to run production there, but 
rather just enough horsepower to keep up with redo application.

 

Step 5 becomes Shutdown Applications

6. Allow pending transactions to complete

7. Restart restricted, switch redo logs, etc.

8. Shutdown at DC1.

9. Start and make primary at DC2 to make sure nothing boneheaded took place.

 

IF 9. fails, you abort until you can restage the move eliminating whatever 
boneheaded took place.

 

Old 9 regarding rsync for things not in the database still might need to be 
done.

 

Still need outage for the time to move the servers and point the existing DC1 
servers at the relocated primary database,

but you’ve eliminated the time for RMAN out and back in.

 

You gain in that the up to date known good copy of the database is never in 
transit.

While the servers ARE in transport you might make an RMAN backup local to DC2.

 

If you stick with your plan, you probably want to make TWO RMAN backups to 
disjoint disk sets and retain one copy at DC1.

 

”I’m not paranoid, I’ve been a production DBA.” 

 

mwf

 

From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On 
Behalf Of msanjeevk
Sent: Thursday, March 19, 2015 1:23 PM
To: ORACLE-L
Subject: RAC servers as-is move to new DataCenter

 

All,

 

We have 2 node 11.2.0.4 RAC on OEL 6.5 (64bit) using Pure Storage LUN's for ASM 
in DataCenter1(DC1)

 

We do not use ASMLIB. For device persistence use combination of udev and 
multipath.conf

 

Requirement is to move servers(as-is move) --  to new DataCenter2(DC2) which 
has its own seperate Pure Storage Array

 

Public/VIP and SCAN IP's will remain the same after move to new DC2

 

I've checked the possibility of building 2 new servers at DC2 and setup standby 
etc to do cutover with less downtime however been told they don't have budget 
to buy new servers at DC2.

 

At highlevel plan will be - haven't done the POC yet for this:

 

Steps:

1.   Build a single temporary server which has same version at DC2

2.   Request SA to provision storage for Oracle/Grid Home etc to match mounted 
file systems on servers at DC1 and mount them with appropriate name at DC2.

3.   Do initial rsync between file systems at DC1 & DC2

4.   Request SA to provision LUN's from Pure storage and discover them at DC2 
on temporary server

5.   Shutdown applications and database in DC1

6.   Take RMAN backup to disk

7.   Shutdown Oracle cluster services

8.   Request SA to copy the LUN allocated for ASM diskgroup hosting OCR and 
voting disk at DC1 to device with same name to a LUN provisioned at  DC2

9.   Do final rsync between file systems at DC1 & DC2

10.  SA to move physical servers to new DC2

11.  At DC2, SA to bring up RAC servers and discover storage file systems that 
were earlier mounted on single temporary server 

     Permissions and mount points etc will match with how they existed at DC1

12.  SA to discover LUN's allocated (in step4 above) from Pure Storage at DC2

13.  Validate udev and multipath.conf and pure related rule files at the OS to 
make sure the wwid's are updated correctly for those devices

14.  Start cluster -- make sure everything looks good with OCR and voting file

15.  Create ASM diskgroup using devices provisioned in step10 above.

16.  Mount ASM Diskgroup on both RAC nodes to ensure its successful

17.  Restore RMAN back to ASM diskgroup and bring up DB

 

Are there any issues with this approach.

 

I've already reviewed this note:

Exact Steps To Migrate ASM Diskgroups To Another SAN/Disk-Array/DAS/etc Without 
Downtime. (Doc ID 837308.1)

 

But I cannot follow that as Pure Storage SAN is in 2 different data centers and 
our SA mentioned there will be only scp allowed between data center to copy 
files between storage file systems.

 

Also is there a better and efficient way to do this move with Pure Storage 
level LUN's copy between datacenters instead of RMAN backup and restore.

 

Has this been tried by other people in this list before.

 

 

Regards,

Sanjeev.

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