Today I upgrade my server to ubuntu 10 lucid, The first thing that occur to me is the new encrypted method, it's the default line
since it starts with $6$, I figured out it's sha-512 method, so I tried to use mkpasswd tool
mkpasswd -m sha-512 123456
so I add a new line to the shadow file
but it doesn't work! probably dues to the salt, I don't know what it is, so I didn't specify.