Hi everyone! I want to be able to access a folder inside the guest that corresponds to a cloud drive that is mounted inside the guest for security purposes. I have tried setting up a shared filesystem inside Virt-Manager (KVM) with virtiofs (following this tutorial: https://absprog.com/post/qemu-kvm-shared-folder) but as soon as I mount the folder in order for it to be accessible on the guest host the cloud drive gets unmounted. I guess a folder cannot have two mounts at the same time. Aliasing the folder using bind and then sharing the aliased folder with the host doesn’t work either. The aliased folder is simply empty on the host.

Does anyone have an idea regarding how I might accomplish this? Is KVM the right choice or would something like docker or podman better suited for this job? Thank you.

Edit: To clarify: The cloud drive is mounted inside a virtual machine for security purposes as the binary is proprietary and I do not want to mount it on the host (bwrap and the like introduce a whole lot of problems, the drive doesn’t sync anymore and I have to relogin each time). I do not use the virtual machine per se, I just start it and leave it be.

  • chirping@infosec.pubEnglish
    1·
    15 days ago

    I don’t understand what you mean with the content disappearing when you mount the virtiofs on the guest - isn’t the mount empty when bound, untill the guest populates it?

    Can you share what sync client+guest os you are using? if the client does “advanced” features like files on demand, then it might clash with virtiofs - this is where the details of which client/OS could be relevant, does it require local storage or support remote?

    If guest os is windows, samba share it to the host. if guest os is linux, nfs will probably do. In both cases I would host the share on the client, unless the client specifically supports remote storage.

    podman/docker seems to be the proper tool for you here, but a VM with the samba/nfs approach could be less hassle and less complicated, but somewhat bloaty. containers require some more tailoring but in theory is the right way to go.

    Keep in mind that a screwup could be interpreted by the sync client as mass-deletes, so backups are important (as a rule of thumb, it always is, but especially for cloud hosted storage)

    • GathererStuffOPEnglish
      1·
      15 days ago

      I don’t understand what you mean with the content disappearing when you mount the virtiofs on the guest - isn’t the mount empty when bound, untill the guest populates it?

      Sorry I made a mistake in the original post. I wanted to say on the host instead of on the guest. My bad.

      Yes, you are correct, the folder is empty until I log in insde the cloud application on the guest.

      does it require local storage or support remote?

      What do you mean? The cloud drive is a network drive basically. It only downloads files on demand.

      if guest os is linux, nfs will probably do

      This is what others have suggested and what I will probably do if the method below fails.

      podman/docker seems to be the proper tool for you here

      Yesterday I actually tried to spin a podman container hoping it would work but I encountered the following problem when trying to propagate mounts: https://lemmy.ml/post/22215540

      Could you please assist me there if you have further ideas? Thank you :)

      Keep in mind that a screwup could be interpreted by the sync client as mass-deletes

      I am VERY aware of this *sweating*