hi am geting this error when installing oracle database

i try to follow this https://matthiashoys.wordpress.com/2012/06/19/increasing-swap-space-on-oracle-linux/
swapon -s
Filename Type Size Used Priority
none virtual 2097148 0 0
[root@hostname ~]# mkswap -c /dev/sdb
/dev/sdb: No such file or directory