Volume recovery from snapshot ebs

I created an ebs snapshot with the data on it. Then I tried to create the volume from the snapshot and attach it to the instance. However, when I try to install the volume (with data), it says

mount: wrong fs type, bad option, bad superblock on /dev/xvdg,
   missing codepage or helper program, or other error
   In some cases useful info is found in syslog - try
   dmesg | tail  or so

And if I try to execute mkfs, will all data be lost correctly?