Hello, Qemu has support for reconnect-delay parameter, that allows for the qemu nbd client to retry failed NBD operations. This is useful if you are running a custom NBD server and want to update the server without failing requests. Unfortunately, the only way to supply these flags is at domain creation via qemu commandline passthrough feature [1]; there is no way to supply them when eg hotpluggin a disk via eg: "virsh attach-device ..." Is there interest in libvirt for a patch that supports qemu "reconnect delay" param? What would be the best way to move forward with such a patch? I think the param can be supported in either the device definition (eg: the <reconnect enabled='yes' timeout='10'/> option already exists for disk type="vhostuser"), or globally via the qemu.conf configuration file. Thank you for your time [1] https://libvirt.org/kbase/qemu-passthrough-security.html#xml-document-additions