Linux Mount Point Monitoring: NFS, CIFS, Bind Mounts and Stale Detection

Mount points are the foundation of Linux filesystem access, yet many sysadmins overlook mount monitoring until a stale NFS mount causes a cascading service failure. Understanding your mount landscape — from local block devices to remote NFS/CIFS shares — is essential for maintaining reliable server infrastructure.

Understanding Linux Mounts

Every accessible filesystem on Linux is attached to the directory tree via a mount point. The kernel maintains the mount table in /proc/mounts, which reflects the current state of all mounted filesystems.

# View all mounts
mount
cat /proc/mounts

# Tree view with findmnt
findmnt

# Filter by filesystem type
findmnt -t ext4,xfs
findmnt -t nfs,nfs4,cifs

Network Mount Monitoring

Network mounts (NFS, CIFS, GlusterFS, SSHFS) add complexity because they depend on network connectivity and remote server availability:

# Mount NFS share
mount -t nfs server:/export/data /mnt/data

# Mount CIFS/SMB share
mount -t cifs //server/share /mnt/share -o username=admin

# Check NFS mount status
nfsstat -m

Stale Mount Detection

Stale mounts occur when the remote server becomes unreachable while the mount is still registered. A stale NFS mount can cause processes to hang indefinitely:

# Test for stale mount (times out if stale)
timeout 5 stat /mnt/nfs-share

# Force unmount stale mount
umount -l /mnt/stale-share    # Lazy unmount
umount -f /mnt/stale-share    # Force unmount

Automated Mount Monitoring

pip install dargslan-mount-monitor
dargslan-mount report      # Full mount report
dargslan-mount network     # Network mounts only
dargslan-mount stale       # Detect stale mounts
dargslan-mount usage       # Disk usage per mount

Best Practices

• Use soft and timeo options for NFS mounts to prevent indefinite hangs
• Monitor mount health in your alerting system
• Use autofs for on-demand mounting of network shares
• Regularly check for stale mounts, especially after network maintenance
• Document all mounts in /etc/fstab with nofail for non-critical mounts

Download our free Mount Point Monitoring Cheat Sheet for essential mount commands. Browse our Linux & DevOps eBooks for comprehensive filesystem knowledge.