Kernel Modules won't load after moving VM from NFS (QCOW2) to LVM-Thin (RAW)


Sep 18, 2019
I have built several Debian Buster VMs, to include the nfs-common package. They worked fine when then were on my NAS (NFS share), ie. could mount NFS shares from another system. When I move the VMs disk to my local LVM-Thin datastore (local to the Proxmox 6 hypervisor), I can no longer mount NFS shares.

After looking into the problem found that the NFS module won't load in the kernel any more. Trying to load the module manually gives the following error:

113.porthos:~ # modprobe nfs
modprobe: ERROR: could not insert 'nfs': Key was rejected by service

Does anyone have any ideas how to fix this?

Thanks in advance.
i cannot imagine what the underlying vm storage could possibly have to do with kernel modules (aside from corrupt storage)
Agreed, this is very strange. I just created a VM on the LVM-Thin datastore (NFS worked fine there) then moved the disk to the NFS store. No problems, the nfs kernel module would still load. Then I moved the same image back to the LMV-Thin datastore, and sure enough, can't load the nfs kernel module anymore. This was very easy to duplicate.

Also to note, the image format on NFS is qcow2, but on the LVM-Thin it is raw.
Last edited:
Just in case someone else runs into this problem, I was able to fix it by booting from an older kernel the doing the following:

apt purge linux-image-4.19.0-6-adm64
apt install linux-image-4.19.0-6-amd64

Then rebooting. This resolved the problem.


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