Chapter 14. Sharing files between the host and its virtual machines

Procedure

1. On the host, export a directory with the files you want to share as a network file system (NFS).

   1. Obtain the IP address of each virtual machine you want to share files with. The following example obtains the IPs of testguest1 and testguest2.

      # virsh domifaddr testguest1
      Name       MAC address          Protocol     Address
      ----------------------------------------------------------------
      vnet0      52:53:00:84:57:90    ipv4         192.168.124.220/24
      
      # virsh domifaddr testguest2
      Name       MAC address          Protocol     Address
      ----------------------------------------------------------------
      vnet1      52:53:00:65:29:21    ipv4         192.168.124.17/24

   2. Edit the /etc/exports file on the host and add a line that includes the directory you want to share, IPs of VMs you want to share with, and sharing options.

      Shared directory VM1-IP(options) VM2-IP(options) [...]

      For example, the following shares the /usr/local/shared-files directory on the host with testguest1 and testguest2, and enables the VMs to edit the content of the directory:

      /usr/local/shared-files/ 192.168.124.220(rw,sync) 192.168.124.17(rw,sync)

   3. Export the updated file system.

      # exportfs -a

   4. Ensure the NFS process is started:

      # systemctl start nfs-server

   5. Obtain the IP address of the host system. This will be used for mounting the shared directory on the VMs later.

      # ip addr
      [...]
      5: virbr0: [BROADCAST,MULTICAST,UP,LOWER_UP] mtu 1500 qdisc noqueue state UP group default qlen 1000
          link/ether 52:54:00:32:ff:a5 brd ff:ff:ff:ff:ff:ff
          inet 192.168.124.1/24 brd 192.168.124.255 scope global virbr0
             valid_lft forever preferred_lft forever
      [...]

      Note that the relevant network is the one being used use for connection to the host by the VMs you want to share files with. Usually, this is virbr0.

2. On the guest OS of a VM specified in the /etc/exports file, mount the exported file system.

   1. Create a directory you want to use as a mount point for the shared file system, for example /mnt/host-share:

      # mkdir /mnt/host-share

   2. Mount the directory exported by the host on the mount point. This example mounts the /usr/local/shared-files directory exported by the 192.168.124.1 host on /mnt/host-share in the guest:

      # mount 192.168.124.1:/usr/local/shared-files /mnt/host-share

Procedure

1. On the host, create a Samba share and make it accessible for external systems.

   1. Add firewall permissions for Samba.

      # firewall-cmd --permanent --zone=public --add-service=samba
      success
      # firewall-cmd --reload
      success

   2. Edit the /etc/samba/smb.conf file:

      1. Add the following to the [global] section:

         map to guest = Bad User

      2. Add the following at the end of the file:

         #=== Share Definitions ===
         [VM-share]
         path = /samba/VM-share
         browsable = yes
         guest ok = yes
         read only = no
         hosts allow = 192.168.122.0/24

         Note that the hosts allow line restricts the accessibility of the share only to hosts on the VM network. If you want the share to be accessible by anyone, remove the line.

   3. Create the /samba/VM-share directory.

      # mkdir -p /samba/VM-share

   4. Enable the Samba service.

      # systemctl enable smb.service
      Created symlink /etc/systemd/system/multi-user.target.wants/smb.service → /usr/lib/systemd/system/smb.service.

   5. Restart the Samba service.

      # systemctl restart smb.service

   6. Allow the VM-share directory to be accessible and modifiable for the VMs.

      # chmod -R 0755 /samba/VM-share/
      # chown -R nobody:nobody /samba/VM-share/

   7. Add the SELinux Samba sharing label to /etc/samba/VM-share/

      # chcon -t samba_share_t /samba/VM-share/

2. On the Windows guest operating system, attach the Samba share as a network location.

   1. Open the File Explorer and right-click "This PC".

   2. In the context menu, click Add a network location.

      
   3. In the Add Network Location wizard that opens, select "Choose a custom network location" and click Next.

   4. In the "Internet or network address" field, type host-IP/VM-share, where host-IP is the IP address of the host. Usually, the host IP is the default gateway of the VM. Afterwards, click Next.

      
   5. When the wizard asks if you want to rename the shared directory, keep the default name. This ensures the consistency of file sharing configuration across the VM and the guest. Click Next.
   6. If accessing the network location was successful, you can now click Finish and open the shared directory.

Procedure

1. In the Virtual Machines interface, click the VM with which you want to share files.

   A new page opens with an Overview section with basic information about the selected VM and a Console section.

2. Scroll to Shared directories.

   The Shared directories section displays information about the host files and directories shared with that VM and options to Add or Remove a shared directory.

   

3. Click Add shared directory.

   The Share a host directory with the guest dialog appears.

   

4. Enter the following information:

   • Source path - The path to the host directory that you want to share.
   • Mount tag - The tag that the VM uses to mount the directory.

5. Set additional options:

   • Extended attributes - Set whether to enable extended attributes, xattr, on the shared files and directories.

6. Click Share.

   The selected directory is shared with the VM.

Procedure

1. In the Virtual Machines interface, click on the VM from which you want to remove the shared files.

   A new page opens with an Overview section with basic information about the selected VM and a Console section.

2. Scroll to Shared directories.

   The Shared directories section displays information about the host files and directories shared with that VM and options to Add or Remove a shared directory.

   

3. Click Remove next to the directory you wish to unshare with the VM.

   The Remove filesystem dialog appears.

   

4. Click Remove.

   The selected directory is unshared with the VM.