Problem & solution are external to Oracle.
You might be successful but you'll likely have to be persistent in order to work through all in inherent incompatibilities involving what you are attempting.
What do you hope to do with the RMAN backup files once they reside on Windows filesystem?
How do I ask a question on the forums?
I need to know where I can start to look if it is a OS/filesystem error.
Daily backups need to go to the shared drive.
I'd start by looking at the permissions on /u03
then look at the permissions on /u03/totes
then look at same from the Windows side.
Instead of having rman write directly to the shared drive, can you write to a local linux file system, then copy the files with os-level utilities?
You might trying starting rman (not as oracle) and go into another session. grep a long ps output for rman. See who the user is? Since Oracle tends to run things setuid, whoever the unix user that is running the backup has to have privileges to write to the device. If you are running rman as oracle, perhaps there is a different mapping of user to userid on the share.
Edit: Here's another odd thought. If you've done this repeatedly and Oracle came up with the same filename, owned by a different user, it might not have the permission to remove/overwrite it (or directories if you are running into the controlfile autobackup).
To put a closure on this thread, I spoke with the IT team to look at the privileges on the OS level on both the windows and linux machines and they confirmed that there was full access provided to the shared mount. So, as a last resort I opened a ticket with Oracle and this is the final reply I got from them.
As stated by the Oracle Rep:
What was discussed is that one can create backups to NFS-shared mounts or windows shared drives but in both case the source where Oracle database is running and the destination directory where you intend to take backups, must be the same platform. Any other configuration might work but it will not be supported since it is not documented as such.
Thanks for all the help. If anyone has any other inputs kindly post them.
The acronym is YOYO - You're On Your Own.
Thanks for the update. I'm still wondering about files already existing though, that's a matter of a user with higher privilege blocking one with lower, even though both have privilege. You can guess I've run across this mistake
# echo "blabla" > blabla
# ll blabla
-rw-rw-rw- 1 root sys 7 Sep 20 09:16 blabla
# chmod 700 blabla
jeg$ echo "blabla" > blabla
/usr/bin/ksh: blabla: cannot create