One use case for my new Unraid server is as the primary storage of 20+ years of digital photos. They are currently on a USB 3.0 drive formatted for MacOS, with a total volume of around 1.5 TB.

What are my best options for getting them on my array and verify that all files have been correctly written?

After some back and forth with Claude, I've this CLI command for Rclone

rclone copy /Volumes/external_usb_drive /Volumes/share_on_unraid \
  --progress \
  --checksum \
  --transfers 8 \
  --checkers 16 \
  --stats 5s \
  --stats-one-line \
  --exclude ".MYLock*" \
  --exclude "*.tmp" \
  --exclude "*.lock"

Are there better alternatives, with either Rclone or other tools?

And if I go with Rclone as above, should I do this subfolder by subfolder (photos stored in yyyy/mm folders on the usb drive) or am I good to go with everything at once?

You could use rsync as it does a Check during transfer. From the rsync manual:

"Note that rsync always verifies that each transferred file was

correctly reconstructed on the receiving side by checking a whole-file checksum that is generated as the file is transferred,"

I have used rsync to move more than 100TB of data over several years without an issue. (It was designed to able to move data between computers via WAN that could easily be on different continents!)

I believe the " -c " switch could be used in a second pass to double verify the transfer but it would be time consuming.

Thanks! Do you have any idea on how Rsync vs Rclone would differ for this use case?

7 hours ago, thoresson said:

Thanks! Do you have any idea on how Rsync vs Rclone would differ for this use case?

Google rclone vs rsync

I have never used rclone. A very quick look suggests that rclone is required on only one end and designed for cloud backup situations. Rsync has to be installed on both the source and destination. (BTW, it also appears that rclone does do hash checks on the files transferred. IF you are wanting to use the hashing function, you may want to check make sure it is the default and not switch option.)