How to Mount a Windows Share in Linux

In this tutorial we will be discussing different ways to connect to a Microsoft share form Linux. Before we dive in I think it is important to understand the different terminology used when talking about Samba, SMB and CIFS shares.

SMB vs CIFS vs SAMBA

SMB (Server Message Block) is a protocol used for network file sharing. It was originally designed at IBM in the 1980's.

CIFS (Common Internet File System) is a implementation of SMB that was created by Microsoft.

SAMBA is an open source software suite and set of utilities used by UNIX/Linux to communicate with Microsoft Windows systems.

From the average user stand point SMB and CIFS can be used interchangeably. As you will see below, we will connect to the same share using both SMB and CIFS.

Mount a Windows Share Using GUI (Files / Nautilus)

You can easily connect to a Windows share using the Files application (formerly known as Nautilus) that ships with Gnome. For the sake of clarity, we will call it Nautilus.

Open the Nautilus application and select "Other Location" from the left places panel.

At the bottom of the screen you will see "Connect to Server" with a box asking for you to enter the server address. Inside that box is a diamond with a question mark in it that you can click for some help.

As you can see in the pop-up, server addresses are made up of a protocol prefix and an address. On my Windows machine named "MyMuse" I created a share called "SharedDocs". So inside that entry box we will use:

smb://mymuse/shareddocs

We can also use the IP address:

smb://10.0.0.3/shareddocs

This will bring up a dialog box asking for authentication credentials.

Select the "Registered User" radio button and enter your details. You have three options for storing your password.

• Forget password immediately - This will log you in and and soon as your session is over you will be required to provide your credentials again.
• Remember password until you logout - Remember your password until you explicitly logout.
• Remember forever - This option will store the credentials and allow you to easily return to the share.

Once you are connected, Nautilus will show the location on the left panel allowing easy access to the share.

Be aware that once that connection is closed you will have to go back to "Other Locations" and use the drop down box to reconnect. If you want to make the share persistently accessible from the left menu you will need to add a bookmark.

NOTE: If you do not want to type your credentials every time ensure that you select "Remember Forever" when authenticating to the share.

To add a bookmark, connect to the share then right click it in the left panel and select "Add Bookmark".

If you have a lot of shares, or multiple shares on the same device, it will be hard to differentiate them. You can rename them to something more user friendly by right clicking on the bookmark and selecting "Rename...".

Now we can easily navigate to our share as the name is clearly visible and easy to identify.

Mount A Windows Share Using Command Line

Using the mount.cifs Command

You can easily mount a cifs share from the command line using the mount.cifs command. Using the mount command requires root privileges.

First, create a directory to mount the share:

mkdir /mnt/cifs

Use the mount.cifs command to mount the share at the created directory.

# mount.cifs //MyMuse/SharedDocs /mnt/cifs -o username=putorius,password=notarealpass,domain=PUTORIUS

# cd /mnt/cifs/
# ls -lrt
 total 284
 -rwxr-xr-x. 1 root root 287600 Mar  3 11:54 'Server Message Block - Wikipedia.pdf'

You can use the IP address as well.

# mount.cifs //10.0.0.3/SharedDocs /mnt/cifs -o username=putorius,password=notarealpass,domain=PUTORIUS

Alternatively, you can use mount -t cifs with the same syntax.

# mount -t cifs //10.0.0.3/SharedDocs /mnt/cifs -o username=putorius,password=notarealpass,domain=PUTORIUS

# ll /mnt/cifs/
 total 284
 -rwxr-xr-x. 1 root root 287600 Mar  3 11:54 'Server Message Block - Wikipedia.pdf'

Automatically Mount CIFS Share at Boot

Mount CIFS Share at Boot Using /etc/fstab

You can add your CIFS mount point in /etc/fstab and have the system mount it during boot. However, there are some considerations to make. If the share is not available at boot time the system will hang until the mount attempt times out, or worse, refuse to boot. This will cause a delay in accessing the system. To avoid this you can use autofs (next section). Also mounting it via fstab requires you to put your credentials somewhere in plain text. You have two options when using fstab to mount a CIFS share.

1. Put the credentials in the fstab file itself - This is a huge security risk as fstab is readable by any user. Someone can simply cat the file and see your credentials. IT IS NOT RECOMMENDED!
2. Use a credentials file - This entails saving your credentials in a separate file which can then be protected by permissions. Although your credentials will still be saved in plain text, someone would need root permissions to read them.

Because of the high risk of the first option, we will not even discuss how to do it. It is easy enough to use a credentials file.

First, create a hidden file in root's home directory (/root/). You can call this file whatever you like. Most people call it .smbcreds or similar. In this file you need two lines, one containing "username=<your-username>" and one containing "password=<yourpassword>".

Example:

# vi /root/.smbcreds
# cat /root/.smbcreds 
 username=putorius
 password=notarealpass

Now set the permissions so it is only readable by root:

# chmod 400 /root/.smbcreds

Now edit the /etc/fstab file and add the following information:

• Remote server share address (//mymuse/shareddocs)
• Local mount point (/mnt/cifs)
• Filesystem type (cifs)
• options (credentials file=/root/.smbcreds)
• dump option (0)
• check option (0)

Example fstab, last line showing the CIFS mount point.

[root@putor ~]# cat /etc/fstab 
 /dev/mapper/putor-root  /                       ext4    defaults        1 1
 UUID=c13ac7eb-9e4b-4ee9-b0d4-4302c4030323 /boot                   ext4    defaults        1 2
 /dev/mapper/putor-home  /home                   ext4    defaults        1 2
 /dev/mapper/putor-swap  swap                    swap    defaults        0 0
 //MyMuse/SharedDocs    /mnt/cifs       cifs    credentials=/root/.smbcreds 0 0

Mount CIFS Share using AutoFS

The most obvious benefit of using autofs is that the share is only mounted when being accessed. If it is unavailable it will not effect your system when it boots.

Using autofs has the same credentials issues described above with fstab. It is also necessary to store your password in plain text when using autofs for cifs shares.

Installing autofs Package

Install autofs in CentOS 7, or Red Hat 7:

# sudo yum install autofs cifs-utils -y

Install autofs in Ubuntu 18:

# sudo apt-get install autofs cifs-utils -y

Let's configure autofs to mount our Windows share.

Create Credentials File

First, ensure you create the credentials file as described above:

# vi /root/.smbcreds
# cat /root/.smbcreds 
 username=putorius
 password=notarealpass

DO NOT forget to set the permissions:

# chmod 400 /root/.smbcreds

Get UID for User

Now, let's get our user accounts uid so we can tell autofs to mount the share as our user instead of root.

$ id -u <username>

Example:

$ id -u savona
 1000

Edit auto.master Map File

Edit the /etc/auto.master configuration file. In this file we will provide a map of directories to shares for autofs to use. Add the following line to the file:

/mnt       /etc/auto.shareddocs

The first part of the above line is the directory we are using as a mount point (you can create a custom directory if you wish). The second is the file that autofs should look in for instructions on how to connect to the resource and mount it.

Create the Shares File

Next edit or create the /etc/auto.shareddocs file and add the following:

shareddocs -fstype=cifs,rw,credentials=/root/.smbcreds,uid=1000 ://10.0.0.3/shareddocs

Restart the Service

Now we must restart the autofs service so it reads the new configuration.

systemctl restart autofs

Test and Verify

Now, let's look in the /mnt directory.

ll /mnt
 total 0

The shareddocs directory doesn't exist until you try to access it (auto fs). If everything above was followed, we should be to cd into that directory even though we do not see it. The directory will be dynamically created as it is accessed.

# cd /mnt/shareddocs
# ll
 total 284
 -rwxr-xr-x. 1 savona root      0 Mar  3 14:20 ok
 -rwxr-xr-x. 1 savona root 287600 Mar  3 11:54 Server Message Block - Wikipedia.pdf

Bob's your uncle.

Conclusion

In this article we covered 3 different ways to mount your Windows shares in Linux. You should now be able to mount an SMB share via the GUI, manually on the command line, automatically on boot and with autofs.

An important point I would like to stress is make sure you protect your credentials. I hope you enjoyed this tutorial, please leave feedback or questions in the comments below.

Other SMB and CIFS Resources

• CIFS vs SMB: What's the Difference
• Server Message Block - WikiPedia
• Why You Should Never Again Utter the Word, "CIFS"