Confused on Storage ALLOC/USED

[Nomad]

Code:

NAME		   SIZE  ALLOC   FREE  EXPANDSZ   FRAG	CAP  DEDUP  HEALTH  ALTROOT
ZED3		  32.5T  13.5T  19.0T		 -	 0%	41%  1.00x  ONLINE  /mnt
freenas-boot  14.5G   847M  13.7G		 -	  -	 5%  1.00x  ONLINE  -

NAME															USED  AVAIL  REFER  MOUNTPOINT
ZED3														   8.99T  12.0T   517G  /mnt/ZED3
ZED3/.system												   88.7M  12.0T   192K  legacy
ZED3/.system/configs-debef3299b91473da16edb313eeb1ae6		  83.8M  12.0T  83.8M  legacy
ZED3/.system/cores											 2.02M  12.0T  2.02M  legacy
ZED3/.system/rrd-debef3299b91473da16edb313eeb1ae6			   176K  12.0T   176K  legacy
ZED3/.system/samba4											 751K  12.0T   751K  legacy
ZED3/.system/syslog-debef3299b91473da16edb313eeb1ae6		   1.77M  12.0T  1.77M  legacy
ZED3/Movies													2.75T  12.0T  2.75T  /mnt/ZED3/Movies
ZED3/Music													  176K  12.0T   176K  /mnt/ZED3/Music
ZED3/TV														4.78T  12.0T  4.78T  /mnt/ZED3/TV
ZED3/backups													979G  12.0T   979G  /mnt/ZED3/backups
freenas-boot													846M  13.2G	64K  none
freenas-boot/.system										   8.57M  13.2G	35K  legacy
freenas-boot/.system/configs-3bc724bbb18d493585697320a07060e7  8.39M  13.2G  8.39M  legacy
freenas-boot/.system/cores									   29K  13.2G	29K  legacy
freenas-boot/.system/rrd-3bc724bbb18d493585697320a07060e7		29K  13.2G	29K  legacy
freenas-boot/.system/samba4									  68K  13.2G	68K  legacy
freenas-boot/.system/syslog-3bc724bbb18d493585697320a07060e7	 29K  13.2G	29K  legacy
freenas-boot/ROOT											   830M  13.2G	29K  none
freenas-boot/ROOT/Initial-Install								 1K  13.2G   825M  legacy
freenas-boot/ROOT/default									   830M  13.2G   827M  legacy
freenas-boot/grub											  6.84M  13.2G  6.84M  legacy

SIZE RAW in TB not TiB so 32.5 instead of 36, Check got that.
FREE vs AVAIL Parity (However I'm in Z2 so I thought this would be 12T not 7T???
ALLOC 13.5T but Dataset shows 9T used. No snapshots. Where is the other 4.5T???

Nothing is stored under /mnt/ZED3 other than the ZED3/<datasets> and some small scripts I use to monitor the pool.

PLZ HALP!!!

 

[kdragon75]

Reported free space does not exclude space that will be used for parity. Space allocated could include space that's reserved for datasets among other things. how many drives do you have in your RAIDZ2 pool? If I remember available is free-parity. Also ZFS has to save block checksums somewhere.

Someone please correct me if i'm wrong!