RMAN Creating In-Progress Backup Files as Hidden (Doc ID 2215563.1)

Last updated on JULY 06, 2021

Applies to:

Goal

Within 12.1.0.2 version and higher, Recovery Manager (RMAN) creates in-progress files are created as Hidden.

After the backup piece creation completes, the file becomes a regular file.

Consider the following example of RMAN cold/offline backup script:

This is a code issue within Oracle 12.1 with the developers implementation of DNFS. This behavior may change in Oracle 12.2.

The workaround is to either disable DNFS or use the "insecure" function.

DNFS (Direct NFS) 12c Database Cannot Be Mounted Due To "ORA-17500: ODM err:Operation not permitted" (<Note 1966267.1>)

1) In Oracle Database 12.1 (12c) release, DNFS (Direct NFS) is enabled/used by default, which uses ports higher than 1024, as such they fail with default exports option,

which honors requests from ports lower than 1024. From the "exports" man page, it states:

Secure This option requires that requests originate on an internet port less than IPPORT_RESERVED (1024).
This option is on by default. To turn it off, specify insecure.

2) This will not impact all NAS servers, but those that restrict the port range, will need to be remounted with the 'insecure' option, e.g.

from:
(rw,no_root_squash)
to:
(rw,no_root_squash,insecure)

3) This NFS backend option called 'insecure' is needed because the 12c Oracle binary is linked with dNFS by default.

4) However, 'insecure' NFS option is not required if DNFS (Direct NFS) is disabled.

5) Official 12c documentation states:

“Oracle® Database Installation Guide
12c Release 1 (12.1) for Linux

=)> 8.4.10.1 About Direct NFS Client Configuration

For NFS servers that restrict port range, you can use the insecure option to enable clients other than root to connect to the NFS server.

6) Also, this behavior and requirement is documented in the following bugs (closed as non-bugs):

Bug 16740594: 12.1 REQUIRES BACKEND NFS SERVER TO MOUNT WITH THE 'INSECURE' EXPORTS OPTION
Bug 16740599: IF DNFS USED CVU SHOULD VALIDATE NFS SERVER MOUNTED W/'INSECURE' EXPORTS OPTION
Bug 14475971: RAC:IMPDP HIT ORA-17503:KSFDOPN:3 FAILED TO OPEN DUMP FILE FROM NFS
Bug 14736884: dbca:db creation got ora-17502/17500 if put dbfile on nfs

These are not bugs, but an implementation.

Solution

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