z890 Logical Channel SubSystems (LCSSs) and support for
Greater than 15 Logical Partitions (LPARs)
The z890 I/O subsystem is a breakthrough in connectivity by providing up to 2 LCSS per server, and each LCSS can support up to 256 CHPIDs when exploitation software is installed. As the z890 is a single I/O cage confi guration it will support up to a maximum of 512 CHPIDs of which up to 420 CHPIDs can be ESCON channels. This support is provided in such a way that is transparent to the programs operating in the Logical Partition (LP). Each Logical Chan- nel SubSystem may have from 1 to 256 CHPIDs and may in turn be confi gured with 1 to 15 Logical Partitions. Each Logical Partition runs under a single LCSS. As with previ- ous zSeries servers, Multiple Image Facility (MIF) channel sharing as well as all other channel subsystem features are available to each Logical Partition confi gured to each Logical Channel SubSystem. The z890 supports up to 30 Logical Partitions. (Note: The lowest Capacity Setting 110 can support up to 240 CHPIDs and up to a maximum of 15 LPARs.)
Up to 30 Logical Partitions 
feature in the I/O cage. CHPID numbers are no longer pre- assigned and it is now a customer responsibility to do this assignment via IOCP/HCD. CHPID assignment is done by associating a CHPID number with a physical location, the PCHID. It is important to note that although it is possible to have 2 LCSSs, there is still a single IOCDS to defi ne the I/O subsystem, each LCSS can support CHPID
IOCP - IOCDS
|
|
|
|
|
|
| Partitions |
|
|
|
|
|
|
|
|
|
|
| Partitions |
|
|
|
|
|
|
| |||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| LCSS0 |
|
|
|
|
| LCSS1 | ||||||||||||||||
|
|
|
|
|
|
| CHPIDs |
|
|
|
|
| CHPIDs | ||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||
| 4F |
|
|
|
| 12 | 52 | EF | 00 | 02 | 12 | 2F | EF | ||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
HCD - HSA or IOCDS - HSA
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Up to 256 |
|
| Up to 256 | ||||||||||
LCSS0 CHPIDs | LCSS1 |
| CHPIDs | ||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Physical Channel IDs (PCHIDs) SubSystem
In order to accommodate the support for up to a maximum of 512 CHPIDs on z890 with the Logical Channel SubSys- tem (LCSS) a new Physical Channel ID (PCHID) is avail- able. The PCHID represents the physical location of an I/O
102 |
| 103 | 104 | 110 |
| 200 |
| 201 |
| 202 |
| 2B0 |
| 2C5 |
Physical Channels (PCHIDs)
Note: Crypto no longer requires a CHPID
Logical Channel SubSystem (LCSS) Spanning
The concept of spanning channels provides the ability for a channel to be confi gured to multiple Logical Channel SubSystems and therefore they may be transparently shared by any/all of the logical partitions in those LCSSs.
15