Morning all,

Has anyone noticed a bug that prevents virtiofs share passthroughs working with VMs, where the share is set as exclusive access?

Specifically this GUI error when starting the VM:

internal error: virtiofsd died unexpectedly

 

And this log error:

libvirt: error : libvirtd quit during handshake: Input/output error

 

Workaround is to do something to turn off exclusive shares, such as enabling NFS, but its a weird bug.

 

Anyone else come across this?

 

Thanks!

Re-tested after the 6.12.2 update today, same error persists, same workaround resolves.

VirtioFS doesen't like the simlink to the true disk location that the new exclusive shares feature sets up. Unraid's VM manager automatically points to the simlink location instead of the disk location. The below changes basically bypass the (simlink) middleman and play nice with virtiofs.

 

You can resolve this without the NFS workaround by changing the <source dir=' '/> path in your VM's XML.

 

BEFORE

    <filesystem type='mount' accessmode='passthrough'>
      <driver type='virtiofs' queue='1024'/>
      <binary path='/usr/libexec/virtiofsd' xattr='on'>
        <cache mode='always'/>
        <sandbox mode='chroot'/>
      </binary>
      <source dir='/mnt/user/some_share_name'/>
      <target dir='vm_storage'/>
      <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
    </filesystem>

 

AFTER

    <filesystem type='mount' accessmode='passthrough'>
      <driver type='virtiofs' queue='1024'/>
      <binary path='/usr/libexec/virtiofsd' xattr='on'>
        <cache mode='always'/>
        <sandbox mode='chroot'/>
      </binary>
      <source dir='/mnt/cache_ssd/some_share_name'/>
      <target dir='vm_storage'/>
      <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
    </filesystem>

Edited September 12, 20232 yr by Flute777