Mount a host file system inside a KVM virtual machine

 Mount a host file system inside a KVM virtual machine

 

   To mount a host file system inside a KVM virtual machine, the modern and most efficient method is using virtio-fs. Alternatively, for older systems, the 9p (VirtFS) protocol can be used. 

Method 1: Using virtio-fs (Recommended)

 

Virtio-fs provides near-native performance by leveraging shared memory between the host and the guest. 

1. Configure Host Shared Memory:
   • Open Virt-Manager.
   • Go to Memory settings and check Enable shared memory.
2. Add Filesystem Hardware:
   • Click Add Hardware > Filesystem.
   • Driver: Select virtiofs.
   • Source path: Enter the directory on your host (e.g., /home/user/shared).
   • Target path: Enter a "mount tag" (a label like myshare).
3. Mount Inside the Guest VM:
   • Create a mount point: sudo mkdir /mnt/shared
   • Mount the filesystem: sudo mount -t virtiofs myshare /mnt/shared.
4. Persistent Mount (Optional):
   • Add this line to /etc/fstab in the guest:
     myshare /mnt/shared virtiofs rw,noatime,_netdev 0 2.

 

 

Method 2: Using 9p (VirtFS)

If your system doesn't support virtio-fs, use the 9p protocol. 

1. Add Filesystem Hardware:
   • In Virt-Manager, add a Filesystem.
   • Driver: Select default or path.
   • Mode: Use passthrough (requires root) or mapped (safer for permissions).
   • Source path: The host directory.
   • Target path: A tag name (e.g., host_share).
2. Mount Inside the Guest VM:
   • sudo mount -t 9p -o trans=virtio,version=9p2000.L host_share /mnt/