I have a few different machines that have different performance and storage qualities (ie. would be bad candidates for clustering).
I’d like to be able to copy files between them, ex. to store ISOs, copy volumes for VM migration, or other tasks. It seems like this is not possible, where the closest emulation is to use a third device with the incus cli and credentials to copy the data through.
That’s correct, Incus doesn’t hold credentials itself, instead it relies on a client to hold the credentials and to drive both source and target server, effectively transferring one time operations and secrets to complete those operations.
Worth noting that the client driving this won’t be relaying the data, the data will still be exchanged directly between the two servers, the client is only there to set up the transfer.
incus copy, incus image copy, incus storage volume copy have three modes - pull, push or relay. If you choose “relay” then the data is passed via the client - useful if firewalls prevent direct communication between the two servers in question.
The default is “pull”, where the destination connects directly to the source.