[SOLVED] group rights for using iso

[informant]

hi all, i have a group since older versions for users. since v8 group rights are different/new.
i have mount a nfs storage with iso´s, how can i add rights to my user group, thats users can only use iso´s, but don´t can remove and edit it and don´t show others on this storage?
my user-group is:

any ideas. my storgae dont have groups added.ps: vm.snapshot dont work since v8 too, i mean it was a problem with same issue. thanks and regards

 

[informant]

Edit: have add PVEDataStoreuser to Storage as @usergroup and in my own usergroup i add permission mapping.use