DRBD and GFS2 Issues

I am using DRBD and I just synced 40GB between 2 nodes for the last 3 days and I am using GFS2 without LVM, I formatted the partition just fine but now I can't mount it

    /sbin/mount.gfs2: invalid device path "/dev/drbd1"
    none: No such file or directory

and this is how I formatted my drbd1

mkfs.gfs2 -p lock_dlm -t cluster-setup:res0 /dev/drbd1 -j 2

and this is my /etc/drbd.conf

    global { usage-count yes; }
    common { syncer { rate 100M; } }
    resource res0 {
      protocol C;
      startup {
        wfc-timeout 20;
        degr-wfc-timeout 10;
        # we will keep this commented until tested successfully:
        # become-primary-on both; 
      }
      net {
        # the encryption part can be omitted when using a dedicated link for DRBD only:
        # cram-hmac-alg sha1;
        # shared-secret anysecrethere123;
        allow-two-primaries;
      }
      on node1 {
        device /dev/drbd1;
        disk /dev/xvdb1;
        address 10.21.127.51:7789;
        meta-disk internal;
      }
      on node2 {
        device /dev/drbd1;
        disk /dev/xvdb1;
        address 10.21.127.52:7789;
        meta-disk internal;
      }
      disk {
        fencing resource-and-stonith;
      }
      handlers {
        #outdate-peer "/sbin/handler";
      }
    }

and this is my mount line in /etc/fstab

/dev/drbd1       /drbd         gfs2    defaults,noatime,nodiratime  0 0

and I even tried to mount using the UUID but I get the same error, also I am facing problem with res name which comes out as not found, any suggestions?

"1:??not-found??" SyncSource Primary/Primary UpToDate/UpToDate C r----"