ZFS mirror is this a bug. Or have I forgotten something?

[berrick]

So in the GUI I have a pool consisting of 2 x 1Tb disks in a mirror and configured as an iSCSI share.

• Whilst doing some testing I let the used disk space go up over the recommended maximum.
• The GUI reflected correctly the amount of free space and showed that the used space was 96% with warning triangle
• After leaving like this for some time I then copied a large amount of data off this pool and then deleted it from the pool

This has all worked with out issue, accept that the GUI still shows used space is 96% when it is now around 70%. I haven't got any snapshots I'm aware of.

So, is this a bug or that I haven't done something I need to to recover the space