Oracle RAC RMAN Backup not writing to NFS Share

Question

run {
    SET nocfau;
    
    ALLOCATE CHANNEL CH0 DEVICE TYPE DISK FORMAT '/nfs/datafile/%U_%T';
    ALLOCATE CHANNEL CH1 DEVICE TYPE DISK FORMAT '/nfs/datafile/%U_%T';
    ALLOCATE CHANNEL CH2 DEVICE TYPE DISK FORMAT '/nfs/datafile/%U_%T';
    ALLOCATE CHANNEL CH3 DEVICE TYPE DISK FORMAT '/nfs/datafile/%U_%T';
    
    BACKUP AS COPY INCREMENTAL LEVEL 0 TAG 'INCR_MERGE' DATABASE;
    BACKUP ARCHIVELOG ALL FORMAT '/nfs/archivelogs/%U' NOT BACKED UP 1 TIMES;
    
    RELEASE CHANNEL CH0;
    RELEASE CHANNEL CH1;
    RELEASE CHANNEL CH2;
    RELEASE CHANNEL CH3;
}

The above is the rman script to run backup for Oracle RAC. I have NFS share that is mounted with following options: rw,user,hard,noac,vers=4

The NFS Server has the following export: NFSv4,rw,no_root_squash,no_all_squash,secure

The issue is that nothing gets written to the NFS share. I can create files, copy large files, but when RMAN is run nothing is copied to the NFS share. The RMAN process runs till it's terminated.

When I do nfsiostat -a it shows 5 mandatory GETATTR requests. Does it mean the Oracle datafiles are not being written in NFS share because the file attributes along with file uid/gid is not being successfully retrieved?

Update: tried running the backup on Oracle 19c RAC setup Get the following RMAN error

RMAN-03009: failure of backup command on CH0 channel at 08/24/2020 16:59:11
ORA-19504: failed to create file "/home/oracle/nfs/ractest/1178998226/full/datafile/data_D-ORAMS19C_I-1178998226_TS-SYSAUX_FNO-3_rhv8m5mt_20200824"
ORA-17503: ksfdopn:11 Failed to open file /home/oracle/nfs/ractest/1178998226/full/datafile/data_D-ORAMS19C_I-1178998226_TS-SYSAUX_FNO-3_rhv8m5mt_20200824
ORA-17500: ODM err: No such file or directory

I ran the rman backup on a local disk they succeed and the datafiles have the group asmadmin. Do backups fail on NFS share becuase the datafile attributes/group information is not being copied to the NFS share? The oracle user is not part of the asmadmin group.

What error did you get? Have you tried to trace RMAN using DEBUG TRACE options? — Sayan Malakshinov
@SayanMalakshinov ORA-06515, ORA-19583 But this happens because I press ctrl-c. Apart from that, I don't see any errors. — AAB

pmdba pmdba · Accepted Answer · 2020-08-20T04:16:47

Your NFS options are wrong for RMAN. For Oracle RAC, they should be as follows:

rw,bg,hard,nointr,rsize=32768,wsize=32768,tcp,vers=3,timeo=600

These options are required, per Oracle documentation. Also, the use of the "noac" option is specifically a problem for RMAN and should not be used.

Oracle RAC RMAN Backup not writing to NFS Share

2 Answers