Overview

The migration from ASM ↔ FS is usually easy process if you know how to do it :), what is important to be moved are:

Mandatory files:

Datafiles

Redolog files

Controlfiles

Spfile/Pfile

Optional Files (but good to migrate as well):

Backups

Archivelogs

Although, the optional files you can always migrate, without restarting/shutting down the server.

Datafiles

Datafiles migration can be done very easily using the “Backup as copy” feature of RMAN as follows:

P.S. That can be done both in Open(Assuming you are in Archivelog mode) and Mount state

Once the backup of the database files has been done, we can switch to copy (that should be done in Mount)

Once we are switched, we can startup our DB.

P.S. If you have done the backup in Open mode you have to recover the copy.

After that, we can continue with the redo log files :)

Redo log files

Unlike the database files, the relocation of the redolog files, we can do completely online :) as follows:

First it is important to get two things:

The sizes of the groups

The current/active/inactive groups

Then it is just adding new group and dropping a group, remember we can drop only INACTIVE groups :)

Controlfiles

Finally we have to re-create the controlfiles, we need to restart the database in order to do that. First we have to do a text backup of the controlfile:

We have to edit the controlfile after that, in order to use only the part which we need: Your controlfile should have ONLY the entries which you need.

After that, we have to modify the pfile, to point to location OUTSIDE of the ASM.

After we modify the pfile, start the instance into a mount state and re-create the controlfile as follows:

Feel free to open the database at this point :)

Appendix

You can use the following procedure to generate all commands if you are lazy: