Re: DBFS and Oracle File system and dataguard

From: Andrew Kerber <>
Date: Tue, 24 Mar 2020 16:09:33 -0500
Message-ID: <>

Thanks for the information. I was thinking about replicating the FS more for demo purposes than actual work. As you noted, there are probably better methods of replicating a file system that dont require an Oracle license.

On Tue, Mar 24, 2020 at 3:09 PM Andy Wattenhofer <> wrote:

> Responses inline
> On Tue, Mar 24, 2020 at 12:55 PM Andrew Kerber <>
> wrote:
>> First, all the examples for setting up DBFS talk about setting it up in
>> its own database. Is it mandatory to configure it in a single use database?
>> Or is there some advantage to doing that? I suppose one would be so you
>> dont have to shut it down every time you start your other database, but are
>> there other reasons?
> If you're planning on mounting the DBFS file store as a filesystem on the
> database server, I think you'll want a separate database. You'll be setting
> up a cluster resource for the dbfs mount and it will have start- and stop
> dependencies. You don't want "crsctl stop resource dbfs_mount" to stop the
> DBFS database if it is also hosting things other than the DBFS mount.
> If you're just planning on accessing the store via remote dbfs_clients, I
> don't think you'll have that problem. It's effectively the same thing as
> having database users connecting to a database and reading and writing
> BLOBs.
> Overall I don't think it is mandatory to have a separate database just for
> DBFS. All of the DBFS functionality is isolated via tablespaces and quotas,
> DBFS file stores, and users and service accounts with specific permissions,
> so there is the ability to fully segregate it from other activity in the
> database.
> I saw an article referencing something called and Oracle File System
>> (OFS). I cant find reference to that except in one place. Can someone
>> point me to documentation on that if it exists.
> Isn't that just the service that exports the DBFS filesystem for mounting
> via NFS? 12.2 doc here:
>> Finally, I plan to put the DBFS system in dataguard. I dont see any
>> reason why I couldnt, just copy the OS configuration and otherwise set up
>> standard dataguard. Is there any reason why I coudn't do that?
> Assuming you don't intend to mount the DBFS filesystem on the standby site
> unless the standby database is switched over to primary mode, I don't see
> why that wouldn't work. But any remote clients that are using the service
> would need to switch to the standby hostname in the event of a failover or
> switchover.
> You could also run a standalone DBFS setup at your standby site and rsync
> between the primary site and it. That is the strategy I chose when I was
> working with DBFS. The benefit is that you don't need to worry about
> service dependencies between sites, because they're independent between the
> sites. And you have a little more flexibility in storing files that are
> unique to the standby site in there.
> Andy

Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'

Received on Tue Mar 24 2020 - 22:09:33 CET

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