title: While trying to create file system on my partition getting an error
body: <p>Iam operating centos 7 on a virtual machine 
  I have  /dev/sdb of size 1G </p>
  
  <p>I used the following command to create a extended partition</p>
  
  <p>fdisk  /dev/sdb</p>
  
  <p>n -- for adding new partition</p>
  
  <p>e -- extended</p>
  
  <p>Partition number --1</p>
  
  <p>First sector --  default </p>
  
  <p>Last sector -- +512M </p>
  
  <p>entered W</p>
  
  <p>partprobe  /dev/sdb</p>
  
  <p>mkfs.ext4  /dev/sdb1  /mnt</p>
  
  <p>Got this error</p>
  
  <p>Mke2fs 1.42.9 (28-dec-2013)
  Mkfs.ext4 : invalid blocks '/mnt' on device '/dev/sdb1'</p>
  
  <p>Not able to figure it out 
  I created a directory /data and tried it in place of /mnt still not worked </p>