Migrating a Synology NAS to a UniFi UNAS Pro 8: Robocopy, SMB Multichannel, and Surprising Performance Traps
Migrating a Synology NAS to a UniFi UNAS Pro 8 with Robocopy, SMB Multichannel
Scott Hanselman migrates his Synology NAS to a UniFi UNAS Pro 8, discovering that Robocopy's /Z flag drastically slows transfers, alternate data streams cause cryptic errors, and SMB Multichannel lets an old Synology with four 1GbE ports hit 250 MB/s. He shares practical Robocopy commands and lessons on tuning for NAS-to-NAS copies.
What I had forgotten is that Microsoft’s current migration guidance specifically warns that /Z should be used cautiously because the extra logging required for restartability can significantly reduce copy performance.