The author encountered unexpected difficulties when migrating files from a Synology NAS to a Ubiquiti UNAS Pro 8 over a high-speed network. Initial attempts using Windows Explorer failed due to filesystem limitations, specifically with filenames containing punctuation. Switching to Robocopy revealed that alternate data streams (ADS), a legacy NTFS feature, were the root cause of the errors. These streams were successfully skipped using Robocopy's /COPY:DATX flag.However, the migration remained slow, prompting the author to investigate further. They discovered that Robocopy's restartable mode (/Z) significantly hampered performance due to its overhead, despite its usefulness on unreliable connections. Removing /Z dramatically improved transfer speeds. The author also explored Robocopy's multithreaded copying (/MT), finding that a moderate number of threads like /MT:4 was beneficial for overlapping I/O operations.For very large files, the unbuffered I/O option (/J) initially recommended by Microsoft, actually slowed down the NAS-to-NAS transfer. Buffered I/O proved to be more effective in this specific scenario. Finally, the author realized that the Synology NAS was capable of higher speeds than initially assumed due to SMB Multichannel, which allowed Windows to utilize all four of the Synology's 1 GbE interfaces simultaneously, aggregating bandwidth and becoming the bottleneck rather than the server itself.