Sorry, about this. I think when migrating PV VMs from a previous system I had issues and "needed" to install "qemu-img" and I did not remember. So removing it, solved the problem. So all my fault. Sorry about this message!!!
@vlamincktr XO PROXY from source is pretty reliable at no cost
either use @acebmxer script or @ronivay
here is a quick tuto on an ubuntu VM
https://omnibox.huducloud.com/shared_article/QJ9y1bRSPj9VTbWp6NKaV7yn/installation-xoa-a-partir-des-sources-github-ronivay
first part is XO CE, second part is XO PROXY CE
beware as you delegate some jobs to XO PROXY, to ever upgrade XO PROXY when you upgrade XOA, so that they have the same backup mechanisms/code
Right, to anyone seeing this - I got the confirmation I needed and can confirm that updating sm and sm-fairlock will allow the master host to mount the XOSTOR SR again properly.
RPU is now resumed and all looks good - Thank you, @dthenot