Re: OFA Structure issue (for gurus only)

Hi Eric,

I don't know AIX, but under HP-UX it is the volume group and logical volume names that need to be unique for the vgimport to work. The filesystem mount points (if any, because we tend to use raw datafiles) can be changed on the fly without difficulty if necessary, and the newer versions of Oracle support this with their datafile rename capability. The real problem would be if you had not used different database names, because OFA specifies a directory level for that, although that could be addressed by changing the database name with a create controlfile and open resetlogs sequence.

The thing I don't like about OFA is that it permits different databases to share disks, which makes disk load balancing awkward. We don't permit that, and so we can put datafiles under /ora/data/dbname/disk_group. The disk_group directory is either a filesystem mount point, or more likely a directory for the symbolic links to all the raw partitions on that disk or disk group. This structure makes it immediately obvious which datafiles are physically co-located, and avoids the ugly plethora of mounts in /.

Regards, Steve Adams

On Mon, 12 May 1997 11:11:47 -0600, eric.san.andres_at_kellogg.com wrote:
> Hi!
>
> I am a new DBA here at our group and I've noticed something that is
>questionable with regards to our OFA structure.
> We have this structure,
> /u020/apps/oracle/......
> that is prevalent on ALL the servers.
>
> Having this structure for one server only is fine, but with the same
>structure for all servers, quite questionable.
> why?
>
> In AIX , there is this option for grouping Physical Volumes (disks) into
>volume groups. And there is also an option that this volume group could be
>exported to another system, PHYSICALLY.
> And this is a recovery option when the CPU crashes and the volume group
>of disks is still intact. Just by simply exporting that volume group and
>transferring that volume group to another system can be done with a snap.
>
> What I am trying to propose is to implement an OFA structue such as
>this:
> /`hostname`/u020/apps/oracle/...
>
> The `hostname` stands for the hostname of a particular server.
> This will complement and exploit the Export/Import of Volume Group
>Capabilities of the UNIX file system. Such that when exporting a set of
>disks there will be no problems in the filesystems configuration to be
>encountered, when importing it, since the hostname mount point will be
>unique in all servers.
>
> I am looking for outstanding comments for this proposition.
>
>Thanks,
>
>Eric San Andres
>eric.san.andres_at_kellogg.com
Received on Wed May 14 1997 - 00:00:00 CDT