Originally posted by: sekar52

Hi I would like to know if it is necessary to have a PowerHA license to have shared VG for coccurrent access between two nodes?

Can I create a shared file system using PowerHa between two nodes

Thanks

Originally posted by: PowerBill

Technically you can create enhanced concurrent mode volume groups without PowerHA software installed.  Those volume groups can be imported on systems that see the associated disks.  The difficulty comes when you try to varyon the volume group.  PowerHA handles the active/passive varyon and the necessary group services setup (including starting gsclvmd).  Even if you did figure out the process for creating the gsclvmd environment, JFS/JFS2 filesystems can not be defined for concurrent access between the systems.

So practically speaking, you use PowerHA with enhanced concurrent mode volume groups.  With that said, true concurrent use of the volume group would require another layer above PowerHA (or gsclmvd) to perform lock management against the volume group.

GPFS is another option that you should consider.

Regards,

Bill

Originally posted by: sekar52

Hi Bill thanks for the response.

I would like to know a few things

1)Do you mean I can concurrently access lv's on two AIX servers without HACMP.How do I do that?

2)Is it possible to create shared file system using HACMP

3)In case i use nfs to mount some mount points from storage to two servers can I use it to share raw lv's.

Basically if want my oracle database files to present in raw lv's can i use NFS as an option.

http://www.oracle-base.com/articles/linux/using-nfs-with-asm.php

In the above link they have created empty files in NFS mount points and they have used it as ASM disks.Can I do the same with raw lv's as well.

Thanks

Originally posted by: PowerBill

Hi...I will answer your questions as you asked them

1) You can, but you have to do what PowerHA does to establish the group services relationships and start gsclvmd, and I would not recommend that. 

2) PowerHA does not provide a shared filesystem.  GPFS is the shared filesystem product on AIX (and supported by Oracle).

3) NFS shares filesystems, not LVs.  So, no you can't use NFS to share your raw LVs for Oracle.

Have a look at this document for the options with Oracle and raw logical volumes:
http://docs.oracle.com/cd/B28359_01/install.111/b28258/stor_rac.htm

I hope this helps...Bill