One of our developers has a VM that uses Flynn with ZFS (and has a lot of filesystems mounted), and when Veeam takes a VMware snapshot, the VM's disk locks up (if I'm already logged in, I can run things that don't touch the disk, like dmesg). If I manually take a VMware snapshot, it completes but it does take nearly 5 minutes. I've disabled application aware and filesystem indexing guest processing to no effect. Support case 02066923.
Is anyone backing up VMs with lots of filesystems (eg Docker hosts) successfully?