mount.cifs

mount.cifs is a command-line utility that allows you to mount a CIFS (Common Internet File System) or SMB (Server Message Block) network share onto your local filesystem. This is useful for accessing files on remote servers as if they were part of your local filesystem. mount.cifs is part of the cifs-utils package on many Linux distributions.

General Usage

mount -t cifs [OPTIONS] //SERVER/SHARE /MOUNT_POINT

Common Options

• -o user=USERNAME: Specify the username for authentication.

• -o password=PASSWORD: Specify the password for authentication.

• -o domain=DOMAIN: Specify the domain for authentication.

• -o vers=VERSION: Specify the SMB protocol version (e.g., 1.0, 2.0, 2.1, 3.0).

• -o rw: Mount the share with read and write permissions.

• -o ro: Mount the share with read-only permissions.

• -o uid=UID: Set the user ID for the owner of the mounted files.

• -o gid=GID: Set the group ID for the owner of the mounted files.

• -o credentials=FILE: Use a credentials file for authentication.

• -o file_mode=MODE: Set the file mode (permissions) for the mounted files.

• -o dir_mode=MODE: Set the directory mode (permissions) for the mounted directories.

Basic Usage Examples

1. Mounting a Share with Username and Password

   sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword

   This command mounts the network share //server/share at the local directory /mnt/mountpoint using the specified username and password.

2. Mounting a Share with a Credentials File

   Credentials File (/path/to/credentials):

   username=myuser
   password=mypassword
   domain=mydomain

   Mount Command:

   sudo mount -t cifs //server/share /mnt/mountpoint -o credentials=/path/to/credentials

   This command mounts the share using the credentials specified in the file.

3. Mounting with Read-Only Permissions

   sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword,ro

   This command mounts the share with read-only permissions.

4. Specifying File and Directory Modes

   sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword,file_mode=0644,dir_mode=0755

   This command sets the file permissions to 0644 and the directory permissions to 0755.

5. Mounting a Share with a Specific SMB Version

   sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword,vers=3.0

   This command mounts the share using SMB protocol version 3.0.

Unmounting the CIFS Share

To unmount a mounted CIFS share, use the umount command:

sudo umount /mnt/mountpoint

Advanced Usage

Mounting with Kerberos Authentication

If your network uses Kerberos for authentication, you can mount the share using Kerberos tickets.

1. Obtain a Kerberos Ticket

   kinit myuser@MYDOMAIN

2. Mount the Share

   sudo mount -t cifs //server/share /mnt/mountpoint -o sec=krb5

Auto-Mounting CIFS Shares

You can configure your system to automatically mount CIFS shares at boot by adding entries to the /etc/fstab file.

Example /etc/fstab Entry:

//server/share /mnt/mountpoint cifs credentials=/path/to/credentials,uid=1000,gid=1000,vers=3.0 0 0

Summary

Command	Purpose	Example Command
sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword	Mount a CIFS share with a username and password	sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword
sudo mount -t cifs //server/share /mnt/mountpoint -o credentials=/path/to/credentials	Mount a CIFS share using a credentials file	sudo mount -t cifs //server/share /mnt/mountpoint -o credentials=/path/to/credentials
sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword,ro	Mount a CIFS share with read-only permissions	sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword,ro
sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword,file_mode=0644,dir_mode=0755	Mount a CIFS share with specific file and directory modes	sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword,file_mode=0644,dir_mode=0755
sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword,vers=3.0	Mount a CIFS share using a specific SMB version	sudo mount -t cifs //server/share /mnt/mountpoint -o user=myuser,password=mypassword,vers=3.0
sudo umount /mnt/mountpoint	Unmount a CIFS share	sudo umount /mnt/mountpoint

Conclusion

mount.cifs is a versatile tool for mounting SMB/CIFS network shares on Linux systems. It provides various options for authentication, permissions, and protocol versions, making it suitable for different network environments and use cases. Understanding how to use mount.cifs effectively can significantly enhance your ability to access and manage network resources in a Linux environment.