I've move a zfs filesystem from a pool made of a bunch or mirror vdevs to another pool made of two raidz1s with the following command
# zfs send -R pool/project@moving | zfs recv tank/project
As far as I understood the manpage, '-R' moves all the metadata as well, including the compression algorithm etc., which is exactly what I see:
# zfs get compression pool/project NAME PROPERTY VALUE SOURCE pool/project compression lz4 local # zfs get compression tank/project NAME PROPERTY VALUE SOURCE tank/project compression lz4 received
So why is the the filesystem on the target pool (tank) over 20% bigger than on the source pool (pool). It's a diference of almost 6TB and I'm curious, where I lost that.