Question about VxVM and VVR over AIX HACMP?

[Gonzalo_Gomez_G]

Hi, I'm trying to figure out what's steps are necesary to acomplish this:

I have a Customer with two datacenters located far from each other, they have theirs primary datacenter with a two AIX Power7 SI -HACMP / GPFS / ORACLE RAC / CLUSTER by the Oracle RAC; they want to replicate this date with VVR to a secondary site with same configuration; the primary site is running at this time and We want to create minimal disturbance in the current environment and help them to replicate the ORacle data to the secondary site with VVR. 

Can We get control of these disk at the primary site with VxVM without any consideration or the customer have to put additional space and transfer current data to the new VxVM volumens?

Thay have to modify additional things inside de HACMP to work with ours VxVM?

They need to control de VVR replication at the command line or SMIT? The HACMP is aware of VVR or not? 

They have AIX 6.1, Oracle 10G, IBM DS5000 FC Storage boxes and 10MB (100Mbps) it's the bandwith of the replication channel?

Thanks for your help,

Best Regards,

Gonzalo Gomez

[mikebounds]

You can't even use AIX JFS/JFS2 with VxVM (see http://www.symantec.com/business/support/index?page=content&id=TECH49600) and therefore you cannot use AIX GPFS with VxVM either.

Techically I believe you can get JFS to work with VxVM, even though it is not supported (see http://www.symantec.com/business/support/index?page=content&id=TECH19886), but GPFS on VxVM wouldn't even work.  This is because for parallel access for VxVM, you need Veritas CVM (Cluster Volume Manager) and this relies on the LLT/GAB stack provided by VCS for communication betweens nodes and CVM requires you use vxfs, it will not support other filesystems - JFS/JFS2 or GPFS.  Also, conversley Veritas CFS is only support on CVM and the same is probably true from an AIX perspective - i.e GPFS is probably only supported on AIX LVM as it will rely on the Volume Management giving parallel access. 

If you want to use VVR, then you have to use VxVM which on AIX means you have to use vxfs.  If you don't need a parallel filesystem, then you can use VxVM/vxfs with HACMP, but if you need parallel filesystem with VVR then you need CVM which uses VCS.  Technically you can buy SFCFS which includes CVM and CFS WITHOUT VCS, but this uses VCS under the hood so it is unlikley it would be supported to use this with HACMP as you would then have 2 clusters in operation.

Mike

[mikebounds]

Just to add, there are tools to converts JFS/LVM to vxfs/LVM, but I don't believe there are any tools to convert GPFS, however with Veritas CFS, actually it is no different from vxfs, so if the same is true for AIX and GPFS is no different to JFS/JFS2 then conversion tools MAY work.  

Also, even though VVR will work with HACMP, I don't know whether it is supported by AIX HACMP.  When failing locally at one site, no VVR commands are necessary which is why it will work - you only need to run VVR commands when you fail across sites and failing across sites is usually manually initiated and therefore you can manually run VVR commands or put VVR commands in a script which I would guess you can get HACMP to run.

Mike

[Gonzalo_Gomez_G]

Thanks for your answer, do you have more recent information? Because We are trying to install version VxVM 5.1 over AIX 6.1 and the reference material that you share it's pretty old.

Thanks,

GG

[sky410]

There is no way to convert GPFS to CVM/CFS, I think you need to full backup and restore it on the CVM/CFS after configuring them.

If you want to do that with minimum downtime, I think you need to prepare additional system temporarly with LPAR.

you can install and configure new OS on the new temporary system and then.

1. Install and configure SFRAC that is a product to support ORACLE RAC.

2. Configure CVM and CFS.

3. Install Oraclel RAC on the SFRAC.

4. Backup and Restore original data from product system to new temporary system.

5. Now, you can configure VVR in this situation with another system that already have same size of storage.

After then, you need to decide if you want to use new system environment or destroy it.

If you want to use the new system with new environment. you can merge the system resources such as cpu, memory, etc. to the new system, Additionally you need to synchronize the data.

Actually, There are some more steps to finish the migration successfully.

Thanks.