question about zpool / zvol size

[link_1983]

Hi I am new to FreeNAS. I created a RAIDZ1 total of four 3TB drives. I send my migrated my data to the new RAIDZ using zfs send receive. Can somebody explain me why i have 5.6TiB used if I only have in reality 4.1TiB of actual data? The difference between the two is 1.5TiB. What is the 1.5TiB of data being used for?

 

[Ericloewe]

The top row is raw disk space and does not consider parity. For a 4-wide RAIDZ1 vdev, that means 33% more space used than in the row below.

 

[link_1983]

It makes sense now. Thank you for answers my questions.