MONERO I created, I also removed other two-default classes, manually. I do use, prefer containerized env/lab, with: -> $ cephadm bootstrap ... all the hardware in VMs (Qemu KVM) which ceph use, is virtualized, as opposed to passed-through. In this lab of mine, used are host's LVM volumes utilized by Qemu XML's as: ... <disk type='block' device='disk'> <driver name='qemu' type='raw'/> <source dev='/dev/cs_whale/ceph'/> ... In guests (hosts for ceph), centos 9, these are as 'virtio_blk': ... [ 1.580490] virtio_blk virtio4: [vdb] 39321600 4096-byte logical blocks (161 GB/150 GiB) ... I get that this is a not a use-case which ceph-devel think of much, if at all. thanks, L.