Key Commands

• showmount
• mount -t nfs
• autofs
• mount -t cifs

# Discover what an NFS server is exporting, before mounting anything
showmount -e nfsserver.example.com

# Create a mount point
sudo mkdir -p /mnt/nfsdata

# Mount an NFS export
sudo mount -t nfs nfsserver.example.com:/exports/data /mnt/nfsdata

# Confirm it mounted
df -h /mnt/nfsdata

# Unmount when done
sudo umount /mnt/nfsdata

# /etc/fstab entry for an NFS mount
nfsserver.example.com:/exports/data  /mnt/nfsdata  nfs  defaults  0  0

# Test it without rebooting, same as any fstab entry (Chapter 10)
sudo mount -a

autofs mounts a share when it's first accessed and unmounts it after a period of inactivity, avoiding the boot-time risk of a static fstab entry.

# Install autofs if not already present
sudo dnf install autofs

# /etc/auto.master — maps a mount point prefix to a map file
/mnt/auto  /etc/auto.mnt

# /etc/auto.mnt — the actual map, defining what mounts where
# key       options                    location
data        -fstype=nfs,rw             nfsserver.example.com:/exports/data

# Enable and start the service
sudo systemctl enable --now autofs

# Accessing this path triggers the mount automatically
ls /mnt/auto/data

# Install the CIFS mount utilities if needed
sudo dnf install cifs-utils

# Mount a Windows/Samba share, prompting for a password
sudo mount -t cifs //fileserver.example.com/shared /mnt/winshare -o username=student

# Store credentials in a protected file instead of typing them each time
sudo mount -t cifs //fileserver.example.com/shared /mnt/winshare -o credentials=/etc/samba/creds

# /etc/fstab entry using a credentials file
//fileserver.example.com/shared  /mnt/winshare  cifs  credentials=/etc/samba/creds  0  0

# /etc/samba/creds contains:
username=student
password=secret

# Lock it down
sudo chmod 600 /etc/samba/creds

# Confirm basic network reachability to the server
ping nfsserver.example.com

# Confirm the export is actually visible
showmount -e nfsserver.example.com

# Check what's currently mounted, and how
mount | grep nfs

# Check recent kernel/service messages related to the mount
journalctl -xe | grep -i nfs

NFS

Network File System, the standard Linux/Unix network file sharing protocol

export

A directory an NFS server makes available to clients

showmount

Lists the exports an NFS server is offering

autofs

Mounts shares on access and unmounts them when idle

SMB/CIFS

The Windows file sharing protocol, implemented on Linux by Samba

credentials file

A root-only file holding the username and password for a CIFS mount

1. What command lets you check what an NFS server is exporting before attempting to mount anything?
2. Why can a permanent /etc/fstab entry for an NFS share be risky at boot time if the server is unreachable?
3. What problem does autofs solve compared to a static fstab entry for a network share?
4. Why should a CIFS credentials file have restricted permissions?
5. A network share mount hangs indefinitely with no error. What's the most likely category of problem?
6. A share mounts successfully, but every file access returns "permission denied." What's the most likely category of problem?
7. Write a command that mounts //fileserver.example.com/shared on /mnt/winshare using the credentials file /etc/samba/creds.