As we all know we can increase the storage system space in our Exadata with 3 ways:
- add a cell to our Exadata
- upgrade Exadata: 1/8 => 1/4 => 1/2 => Full
- add Expansion Rack
Now Oracle allows one another way - change HP disks to HC (4T size) on the same Exadata.
This process is called "Disk Swap Service" and is allowed for X2,X3,X4 machines.
Only hard disks are swapped, flash disks are not touched, they remain.
For 1/4 you need to buy 37 disks (36 will be installed and one is spare).
For 1/2 - 85 and for Full - 169 new 4T disks.
The swapping is carried by ACS.
You need the 188.8.131.52.1 Exadata software version or later (July 2014 Exadata Quarterly Full Stack Patch).
Details are in Oracle note:
Oracle Exadata Database Machine Disk Swap Service Process (Doc ID 1544637.1)