So I have two LaCie 16TB d2 Professional hard drives, NTFS formatted, connected to a Windows 11 host via USB 3. On the root of each drive was a single folder, with file sharing enabled. One was a clone of the other. I had been mounting both shared folders in a Linux VM and using rsync to clone a backup, until I realized it was going very slowly.
So I decided to use robocopy for the clone, because it seemed like it would be a direct, easy solution. But it wasn’t–still excruciatingly slow, even using robocopy on the local machine. Skipping all the troubleshooting I’ve done since then, I’ll just note that all signs point to file sharing being somehow the culprit. So here is where I am stuck:
One drive (the source) still has file sharing enabled, the other (destination) doesn’t. Using either robocopy or File explorer, if I start a copy, the first file (usually the same 5GB file) now flies by at 200MB/s. But once that file completes, the speed tanks to below 1MB/s, and stays there.
Except it’s not always consistent–sometimes nothing goes fast at all. I’ve also tried disabling file sharing on the source, too. Oh, and I have two more of these drives, also a cloned pair, but neither of them has ever been shared on the network. They transfer consistently at ~260MB/s.
What on Earth is happening? I am perplexed. I tested with a different destination drive (shared source), and I got sustained 125MB/s until I killed it. So it has something to do with my specific destination drive, I guess. But I have deleted literally everything from it and started over fresh, so no file sharing config could remain, and it still does this. I ran Windows’ “Error checking” on it and it found no issues.
For reference, here is the most recent iteration of my robocopy command, but I’ve tried many variations, and this behavior happens with File Explorer, too.
robocopy /MIR /COPY:DAT "m:Miao Yin Share\" n:MiaoYinShareMirror /R:1 /W:1 /V /ETA /NDL /LOG:"$env:USERPROFILEDocumentsBackup Logsmiao_yin_mirror_log_$(Get-Date -Format 'yyyyMMdd_HHmmss').txt" /NP /TEE
Thank you in advance for any ideas! I am pulling my hair out!
JMT
