Mount Options
| Option | Value | Description |
|---|---|---|
vers
|
4.1
|
NFSv4.1 for session recovery during failover |
hard
|
- | Retry indefinitely during failover (critical for data integrity) |
timeo
|
300
|
30-second timeout before retransmit (deciseconds) |
retrans
|
2
|
Retransmit attempts before major timeout |
nconnect
|
4-8
|
Multiple TCP connections (requires kernel 5.3+) |
noatime
|
- | Don't update access times |
nodiratime
|
- | Don't update directory access times |
_netdev
|
- | Wait for network before mounting |
Warning:
Do not use soft mount option in production. Soft mounts return I/O errors after timeout (~182 seconds with default settings), which can cause data corruption and application failures. Always use hard for data integrity.
Example fstab entry:
<VIP>:/export /mnt/nfs nfs4 vers=4.1,hard,timeo=300,retrans=2,nconnect=4,noatime,nodiratime,_netdev 0 0Failover behavior comparison:
| Mount Type | During Outage | After Recovery | Data Integrity |
|---|---|---|---|
hard
|
I/O hangs (queued) | Resumes in ~12s | [OK] Guaranteed |
soft
|
I/O fails after ~182s | Error returned | [WARNING] Risk of corruption |
Persistent Mount via fstab
# Add to /etc/fstab
<NFS_SERVER_IP>:/data/rhel /mnt/pure-nfs nfs4 vers=4.1,hard,timeo=300,retrans=2,nconnect=4,noatime,nodiratime,_netdev 0 0Persistent Mount via autofs (Alternative)
# Install autofs
sudo dnf install -y autofs
# Configure /etc/auto.master
echo '/mnt/nfs /etc/auto.nfs --timeout=300' | sudo tee -a /etc/auto.master
# Configure /etc/auto.nfs
echo 'pure-nfs -fstype=nfs4,vers=4.1,hard,timeo=300,retrans=2,nconnect=4,noatime,nodiratime <NFS_SERVER_IP>:/data/rhel' | sudo tee /etc/auto.nfs
# Enable autofs
sudo systemctl enable --now autofs