Distributed file system

[gaurav]

Hi List,
           I have around 50 machines in my lab, since user data is lying 
at  central server (all home directory mounted here)....around 50 to 70% 
storage of local machines is un used .. I was thinking if there was a 
file system using which

   1. Is Distributed across all these  machines
   2. Transparent to users (i.e for users can access thru normal path eg
      /dist/tom/data )
   3. Redundancy factor (Since files are distributed, if one part of
      gets corrupt it should automatically restore)
   4. ACL
   5. Scalable

Is this my wild dream ...or stuff like already exists..if yes the pl 
share.I was evaluating CODA but it is not ready for production release
Any Ideas/Help?

Regards,
Gaurav