Hi Bogdan,
How are you doing?
I hope you did:
1)Resize the LUN in NetApp
2)Rescan from vCenter, may not be required all the time
3)Right click on the datastore >increase Datastore capacity>complete the wizard
4) You should be all good
If not can you please double check the LUN ID and make sure that you expanded the correct LUN by comparing the ID?
The serial number of the LUN can be seen using the below command from ONTAP CLI
cluster::>lun show </vol/lunpath> -fields serial-hex
Also make sure that your Hyperviser supports the increased disk size.
Hope this helps!
Cheers,
DJ-Potsdam
**edited out by the moderator**