Edit: Oh, I misread, is this local? I saw rsync and just though it was a network transfer. What kind of speeds are you getting? Does doing “tar c /original | tar x” or something like that work any faster?
I don’t want to interrupt it, but I could try that next.
The target drive is an ironwolf 7200 HDD, and the source drive is a WD Blue HDD, and I can’t see the speeds clearly because I’m doing through the OMV webUI, but IN THEORY both drives are capable of greater than 5Gb/s file transfer… The seagate drive is connected via SATA to USB dock, running through a usbSS port on the machine, and the WD blue is running directly through a sata port on the controller. With the listed speeds, the transfer could have been completed as fast as within an hour and a half, but we’re coming up on 3 hours now.
I figured it was likely what you mentioned: fragmented files on the volumes and the algorithm being safe by first checking for missing data in the target drive and then sending the bytes, then marking the file complete, ect - but honestly it would surprise me if the added steps would amount to that big of a performance hit. I thought maybe the external sata-to-usb dock could be causing the bottleneck, but that dock is still marketed at 5Gb/s…