Suppose I currently use rsync to back up an internal drive periodically to an external drive. The external drive is usually stored offsite but is periodically brought over and plugged in via USB and then I manually go through the process of starting the rsync.
I'm new to ZFS but wondering if it would be possible to replace the above process with a setup in which the internal drive and the external drive are both part of a RAIDZ pool, so that as soon as I mount the external drive it starts resilvering. If so, how would resilvering compare to rsyncing in terms of performance? And in general, are there any downsides to such a setup?