The Storwize V7000 and SVC have a command line interface that you access via SSH. Every-time you logon, whether it is to transfer a file (using a tool like pscp), issue a single shot command from a script (using a tool like plink) or logon to issue commands interactively (using a tool like PuTTY), you clearly need to authenticate yourself. Since June 2003, the way you did this was to use a public/private key pair, where the SVC or Storwize V7000 had the public key and the SSH client (such as PuTTY) authenticated using the private key (the PPK file).
However with release 6.3 of the SVC and Storwize V7000 firmware, the use of key files is now optional. A user can now authenticate purely by using a password. This includes using your domain ID. So if you defined LDAP to your machine, as I documented here, you could now SSH direct to your Storwize V7000 or SVC, use your Domain user id and password and not go through the key file setup task. Nice!
The choice to continue to authenticate just with an SSH key remains available. If a user has both a password and a configured key file, then either method will work (you only need to use one - not both). Existing scripts will be unaffected by this change, so nothing gets broken because of this.