Cold backup of RAC cluster VM's

[theshepherds]

Hi



I use Esxi as a lab for my Oracle VM’s , research and development etc.

Veeam cannot process the RAC VM virtual disks as they are both shared/multi writer and independent persistent disks. Yes , I can backup the databases , but RAC has a huge amount of config on the system disk etc. It would take a while to rebuild the nodes and then restore the databases.


My solution, albeit a partial non Production solution is to create a new VM , and add the disks used by the RAC Cluster VMs, I then modify the new VM to change the disks to non multi writer , dependent disks.

This VM will never be started , it will remain shutdown. But I can back it up, if I shutdown the parent RAC VM’s. The shutdown and startup is performed by pre and post backup scripts.



Script contents

Code: Select all

c:\Windows\System32\OpenSSH\ssh -v -i c:\users\****\.ssh\id_rsa.pub  -E c:\scripts\shutdown_onedisks_ssh.log -o StrictHostKeyChecking=no root@*******.localdomain  "vim-cmd vmsvc/getallvms | grep RACONEDISK1 | grep -v RACONEDISK1DR | cut -d ' ' -f1 | while read id ; do vim-cmd vmsvc/power.shutdown $id ; done >//vmfs/volumes/SCRATCH/scripts/shutdown_onedisks.log 2>&1" > shutdown_onedisks.log

(MY RAC cluster is 2 node/ 2 VMs , booting off one disk , which has two boot partitions and many partitions for ASM disks for OCR/VOTE/DATA/FRA/OH etc - a single 300GB vmdk used by two VM’s...)

Repeat for all nodes in the cluster.



It’s a cold backup , involves loss of service etc , but scheduled during the night , it does not affect me.



In case you are an Oracle DBA using ESXi and need to backup a RAC cluster so you don't have to spend a lot of time to re-install / re-configure etc, I hope this method will work for you.

[jorgedlcruz]

Hello,
Well, the limitation, in this case, comes more from VMware itself as they are shared vmdks and we can not snapshot them.

I have seen a great guide written by Sudhir, a VMware Senior Architect working on the Oracle division for VMware:

• https://blogs.vmware.com/apps/2021/01/b ... ology.html

It suggests you convert some disks to Independent-persistent, and that of course you take backups of the DBs itself, I would recommend then Veeam Oracle RMAN Plugin. Following the steps from Sudhir, combined with Veeam Oracle RMAN, and using Veeam wherever possible after disks conversions, or even using our Veeam Agents for Linux, would be a really great solution.

Please review all of this, give it a try on a lab environment and let us know.

[theshepherds]

"It suggests you convert some disks to Independent-persistent"

All non OS disks in a RAC setup are independent persistent - you cannot enable the multi writer flag without this being so.

Yes, I have read that article previously
I lost faith when I read this

"Shared vmdk’s/ disks would need to be backed up separately either using Oracle RMAN, a Third-party vendor Agent based software or Storage based backup"

RMAN backs up databases, ie datafiles within the VM , it does not and can not backup vmdk's...The same applies to OS / Agent backups.
The article is flawed in many respects.

As previously mentioned , a RAC cluster involves a lot of setup prior to being able to restore the database. In fact , no restore would be necessary as other nodes are available and have the database open. A RAC VM backup needs a solution that involves backing up all of the disks involved. There is far much more than a database on RAC disks. the OCR , the OLR , the Grid home , the Oracle home , voting disks etc etc etc. My solution , albeit an offline solution , ensures all disks can be backed up by Veeam as it presents the disks as dependent without the multi writer flag.

[jorgedlcruz]

Thank you for sharing the steps and the guide, Adrian.

I hope it does help others then. So far the Oracle Customers I have worked with we always discussed Oracle RMAN but never went to the deep level of OCR, OLR, etc. So it is good to see.

Appreciate the time to put all of this together, hope others using Oracle RAC can chip in with more feedback and questions.

Thanks!