[ceph-users] How to set size for CephFs

Hello, I am new to Ceph and currently i am working on setting up CephFs and RBD environment. I have successfully setup Ceph Cluster with 4 OSD's (2 OSD's with size 50GB and 2 OSD's with size 300GB). But while setting up CephFs the size which i see allocated for CephFs Data and metadata pools is 55GB. But i want to have 300GB assigned for CephFs. I tried using "target_size_bytes" flag while creating pool but it is not working (it saus invalid command). Same result when i use target_size_bytes with (ceph osd pool set) after creating pool. I am not sure if i am doing something silly here. Can someone please guide me on this? Thanks in adv.!