Hi Radek,
The Fractional Reserve setting is disabled by the looks of it.

Here's the output of the df -r command.
FAS2240-02> df -r
Filesystem kbytes used avail reserved Mounted on
/vol/vol0/ 199229440 3880512 195348928 0 /vol/vol0/
/vol/vol0/.snapshot 10485760 237508 10248252 0 /vol/vol0/.snapshot
/vol/v_vdi_datastore9/ 432402476 186069996 246332480 0 /vol/v_vdi_datastore9/
/vol/v_vdi_datastore9/.snapshot 0 0 0 0 /vol/v_vdi_datastore9/.snapshot
/vol/v_vdi_view_datastore9/ 70265404 12336924 57928480 0 /vol/v_vdi_view_datastore9/
/vol/v_vdi_view_datastore9/.snapshot 0 0 0 0 /vol/v_vdi_view_datastore9/.snapshot
/vol/v_vdi_datastore10/ 432402476 384968280 47434196 0 /vol/v_vdi_datastore10/
/vol/v_vdi_datastore10/.snapshot 0 0 0 0 /vol/v_vdi_datastore10/.snapshot
/vol/v_vdi_view_datastore10/ 70265404 11059304 59206100 0 /vol/v_vdi_view_datastore10/
/vol/v_vdi_view_datastore10/.snapshot 0 0 0 0 /vol/v_vdi_view_datastore10/.snapshot