The storage layout provided by the Tachyon Operating System is different from that provided by z/OS. In z/OS, there are separate address ranges used for the LSQA, CSA, SQA, nucleus and other areas. The Tachyon Operating System allocates the next available storage area for any request. However, the Tachyon Operating System does recognize subpools and will not mix allocations for different user subpools on the same page. The Tachyon Operating System supports storage allocation requests for below and above 16 Megabytes. Storage above the 4 Gigabyte “bar” can also be allocated when the Tachyon Operating System runs in architecture level 2.
| Subpools | Attributes |
|---|---|
| 0-127, 240, 250, 251 | Simulated key 8 (not fetch protected, not store protected) |
| 203, 204, 205, 226, 233, 234, 235, 236, 237, 245, 248, 252, 253, 254, 255 |
Simulated key 0 without fetch protection |
| 213, 214, 215, 223, 224, 225, 239, 247 |
Simulated key 0 with fetch protection |
| 129, 131, 227, 229, 231 | Selectable: simulated key 8 (not fetch protected, not store protected) or simulated key 0 with fetch protection |
| 130, 132, 228, 230, 241, 249 | Selectable: simulated key 8 (not fetch protected, not store protected) or simulated key 0 without fetch protection |