I have server2 and server4. I am running out of space on sever2 and no extra slot left. Can I get a new disk and put it on server4 for my index tablespace of Server2? This new disk will only hold index data of server2. If this is doable, how can I do it? How bad the performance will be? Any risk of doing it?
If you do this, some of the tablespaces will be on a different system and access to those will be over the network. This is not recommened as ORACLE may crash if for some reason it can not aceess the datafile located on the other system.
If you are running out of slots, examine replcing your existing disks with higher capacity disks.