–CKD LSSs definitions are configured during the LCU creation.
–FB LSSs definitions are configured during the volume creation.
LSSs have no predetermined relation to physical ranks or extent pools other than their server affinity to either server0 or server1.
–One LSS can contain volumes/LUNs from different extent pools.
–One extent pool can contain volumes/LUNs that are in different LSSs, as shown in Figure
–One LCU can contain CKD volumes/LUNs of different types. For example type 3390 Model 3 and Model 9s.
–LSSs can have a many to many Copy Services relationship as shown by the arrows in Figure
Extent Pool 5
Rank3 |
0 |
3 |
1 |
3 |
1 |
5 |
1 |
2 |
Copy services Relationships
Extent Pool 3
| Rank1 |
0 | 1 |
3 | 1 |
1 | 1 |
0 | 1 |
0 | 0 |
5 | 5 |
| 0 |
1 | 2 |
Figure 9-6 Example of Copy Services relationship between LSSs in the same storage unit
–An entire address group will be either FB or CKD. For example, all 16 LSSs in that group would be either FB or CKD type LSSs.
–Initially there will only be 2 address groups for the DS6000 at GA; however, more will be available at a later time.
–One address group has 4096 addresses (16 LSS x 256 logical volumes = 4096 logical volumes or addresses). This means that if you had two address groups defined in the DS6000, you would have 8192 (2 X 4096 = 8192) addresses or logical volumes.
Attention: The address groups and LSSs are predefined in the DS6000. Initially, they do not have any data format attributes (FB or CKD). Their data format attributes are set when a first logical volume is added to a first LSS in an address group.
When creating a logical volume, the user is prompted to add the volume to an LSS. Adding the volume to an unused LSS will set its data format characteristics (FB or CKD) and also will set the address group data format characteristics. It also sets the data format of the remaining 15 LSSs in that address group.
As an example: When creating a logical volume from an extent pool built with FB ranks, the GUI will prompt in which LSS this FB volume will be placed and will propose a list of LSSs. If the user chooses LSS 14 and if it is the first LUN to be placed in this LSS, then the attributes of address group 1 will be Fixed Block, reserving LSS 10 to 1F for Fixed Block volumes.
160DS6000 Series: Concepts and Architecture
