zfs is great. i wanted to copy my bitcoin node to external drive but didn’t want to shut it off during the copy… so i shut down my node, did a snapshot of the drive (instant), then started it again.

#zfs snapshots keep a readonly, immutable state of the drive in that moment with very little overhead. So my zaps can keep working while i clone the node (snapshots are just symlinks on the drive). Very slick.