qcow2 on CephFS versus RBD

Nov 14, 2019

we wonder which of the following two setups might be the better choice for using Proxmox VE with Ceph:
  • usual: RBD
  • less usual: qcow2 on CephFS
The second setup was mentioned in Thread.

What pros and cons do you come up with?


qcow2 on CephFS does not make sense for me.
To elaborate on Tom's answer. Qcow2 is a copy-on-write (COW) file, that will create double writes on CephFS. This is counter productive for performance. And is a redundant layer, as RBD is already suited for VM/CT image storage.


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