Recover UNDO tablespace in 10g

[vgandhi]

One UNDO datafile went to suddenly offline as a result,it throws error sating that not able to read the file and i created new UNDO and it was assigned as a UNDO tbs but it was not getting assigned so please let me know how to recover this UNDO tablespace.

Version 10.2.0.4
RAC three node database
It happened in third node so no one was able to access the DB.

Thanks
VCarun.

[Tim...]

Hi.

You can recover the tablespace from a backup.

Cheers

Tim...