
Model Type | OS/400 | Number | Extents | Unusable | Usable | |
|
| Device | of LBAs |
| space | space% |
Unprotected | Protected |
| ||||
size (GB) |
|
| (GiB) |
| ||
|
|
|
|
| ||
|
|
|
|
|
|
|
35.1 | 68,681,728 | 33 | 0.25 | 99.24 | ||
|
|
|
|
|
|
|
70.5 | 137,822,208 | 66 | 0.28 | 99.57 | ||
|
|
|
|
|
|
|
141.1 | 275,644,416 | 132 | 0.56 | 99.57 | ||
|
|
|
|
|
|
|
282.2 | 551,288,832 | 263 | 0.13 | 99.95 | ||
|
|
|
|
|
|
|
Note: In Table
When creating the logical volumes for use with OS/400, you will see that in almost every case, the OS/400 device size doesn’t match a whole number of extents, and so some space will be wasted. You should use the figures in Table
Protected versus unprotected volumes
When defining OS/400 logical volumes, you must decide whether these should be protected or unprotected. This is simply a notification to OS/400 – it does not mean that the volume is
protected or unprotected. In reality, all DS6000 LUNs are protected, either
Under some circumstances, you may wish to mirror the OS/400 Load Source Unit (LSU) to a LUN in the DS6000. In this case, only one LUN should be defined as unprotected; otherwise, when mirroring is started to mirror the LSU to the DS6000 LUN, OS/400 will attempt to mirror all unprotected volumes.
Changing LUN protection
It is not possible to simply change a volume from protected to unprotected, or vice versa. If you wish to do so, you must delete the logical volume. This will return the extents used for that volume to the extent pool. You will then be able to create a new logical volume with the correct protection. This is unlike ESS E20, F20, and 800, where the entire array containing the logical volume had to be reformatted.
However, before deleting the logical volume on the DS6000, you must first remove it from the OS/400 configuration (assuming it was still configured). This is an OS/400 task which is disruptive if the disk is in the System ASP or User ASPs
Appendix B. Using the DS6000 with iSeries 331