Rookie space question

[Quiltface]

Got a question about the USED space in the storage view... been searching around and I couldn't quite find an answer for this particular curiosity... i dont think it is an actual issue.

I have 4x 3 TB hard drives in a RaidZ2...

My question is... in the picture below, it shows i have 830.2GiB used and under that I have 402.1Gib used.

I only have data in the "backups" directory so I am not sure why the top level it is saying 830.2, can anyone explain that? Is it due to the compression?

Code:

zfs list                                                                                                        
NAME                                                           USED  AVAIL  REFER  MOUNTPOINT                                     
data                                                           402G  4.71T   140K  /mnt/data                                      
data/.system                                                  2.98M  4.71T   151K  legacy                                         
data/.system/configs-0dc2ca1e7fa9464d8c4d7c4fd81f6855         1.21M  4.71T  1.21M  legacy                                         
data/.system/cores                                             140K  4.71T   140K  legacy                                         
data/.system/rrd-0dc2ca1e7fa9464d8c4d7c4fd81f6855              140K  4.71T   140K  legacy                                         
data/.system/samba4                                            947K  4.71T   947K  legacy                                         
data/.system/syslog-0dc2ca1e7fa9464d8c4d7c4fd81f6855           436K  4.71T   436K  legacy                                         
data/backups                                                   402G  4.71T   402G  /mnt/data/backups                              
data/jails                                                     140K  4.71T   140K  /mnt/data/jails

 

[Bidule0hm]

Please read this post: https://forums.freenas.org/index.php?threads/the-faq.30209/#post-194030 ;)

 

[Quiltface]

Brilliant... thank you so much. Sleeping will be much easier now. :)