The Linux host mounts FlashBlade storage and must be configured specifically for dNFS compatibility. Incorrect mount options are the most common cause of dNFS not activating. These steps should be run to implement a minimum viable configuration:
Create mount points:
mkdir -p /rman
chown oracle:oinstall /rman
chmod 775 /rman
Configure /etc/fstab:
For dNFS, the critical mount option is actimeo=0, which disables attribute caching. Without this, dNFS will not activate.
# Example /etc/fstab entry
10.21.221.21:/rman-backups /rman nfs4 rw,hard,vers=4.1,proto=tcp,timeo=600,actimeo=0 0 0Mount options:
| Option | Requirement | Purpose |
|---|---|---|
| actimeo=0 | Required | Disables attribute caching; dNFS will not activate without this |
| hard | Required | Ensures NFS operations retry on failure; never use soft for critical workloads |
| vers=4.1 or vers=3 | Required | Explicitly sets NFS protocol version |
| proto=tcp | Recommended | TCP transport for reliability |
| timeo=600 | Recommended | 60-second timeout for large I/O operations |
Note: FlashBlade negotiates optimal I/O sizes automatically; do not specify rsize or wsize. The nconnect option is unnecessary when using dNFS, as dNFS manages its own parallel connections.
Mount and verify:
systemctl daemon-reload
mount /rman
mount | grep /rman
# Example output
10.21.221.21:/rman-backups on /rman type nfs4 (rw,relatime,vers=4.1,rsize=1048576,wsize=1048576,namlen=255,acregmin=0,acregmax=0,acdirmin=0,acdirmax=0,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=10.21.227.57,local_lock=none,addr=10.21.221.21)