Got it! I woudl then separate two things – freeing up 16TB disk and migrating the node.
Free up 16TB Disk:
- Shrink your 16TB NTFS drive (Node keeps running)
- Shut down node, and clone entire partition to 12TB disk using disk cloning software, like CloneZilla. This shall go at max sequential speed, 150-200MB/sec, unlike copying by files, so 10 TB worth of node will take about 16 hours. Node is obviously offline during this time.
- Start the node from 12TB NTFS disk.
Now node is running, and you have a spare 16TB disk.
Migration to trunas
- Install the disk to truenas, create a zfs pool and dataset, and enable rsync.
- Start rsync passes from your node machine to truenas. It’s better to use rsync, but if you can’t – robocopy over NFS shall do too.
- Keep repeating rsync passes until the time each next pass takes stops decreasing.
- Shutdown the node.
- Do the last full sync pass (with --delete flag) (this shall take under 10 min)
- Start the node on TrueNAS.
Total downtime – about 17 hours.