INISH deck example

Here is an example of an INISH deck for a TS7700 multi-cluster grid that has devices online in two clusters (other clusters whose devices are not connected to the host might exist for replication purposes). In this example, the composite library has library identification number X'12345' and the first distributed library in the grid has library identification number X'10001' and the second distributed library in the grid has library identification number X'10002'. In this example, each distributed library in the grid has 256 devices for a total of 512. The changes that must be made to the INISH deck to use the optional allocation assist support in JES3 are shown in bold italic text. The INISH deck changes are needed only if the allocation assist functions are to be enabled by specifying JES3_ALLOC_ASSIST=YES in the DEVSUPxx PARMLIB member. Before you enable the allocation assist functions, ensure that all TS7700 Virtualization Engines in the INISH deck are defined with the needed LDXxxxxx names, even if the TS7700 Virtualization is a stand-alone configuration consisting of one distributed library.

In this example, instead of the device statement representing the composite library (as a whole), the device statements are defined at the distributed (or cluster) level and LDXxxxxx names are added (as needed) for each distributed library in a TS7700 Virtualization Engine that has devices connected to the JES3 host.

Device Statements:
Replace:
```
DEVICE,XTYPE=(CLB12345,CA),XUNIT=(1100,*ALL,,OFF),NUMDEV=512
```
With:
```
DEVICE,XTYPE=(DLB10001,CA),XUNIT=(1100,*ALL,,OFF),NUMDEV=256
DEVICE,XTYPE=(DLB10002,CA),XUNIT=(1200,*ALL,,OFF),NUMDEV=256
```
The device statements above are suggested examples that can be used; however, depending on the contiguous device ranges that are available, more than one device statement could be used to represent all of the devices in a composite library and more than one device statement could be needed to represent the devices in a distributed library (and, a given device can only occur in one device statement). For example, if there are not 256 contiguous device addresses starting with 1100, the devices could be split as follows (again, this is just an example):
```
DEVICE,XTYPE=(DLB10001,CA),XUNIT=(1000,*ALL,,OFF),NUMDEV=128             
DEVICE,XTYPE=(DLB10001,CA),XUNIT=(1100,*ALL,,OFF),NUMDEV=128
```
Also, one of the factors used by JES3 in selecting devices for volume mounting is the ADDRSORT parameter on the SETPARAM initialization statement. This parameter specifies that devices are either allocated in the same order as the DEVICE statement defining them (ADDRSORT=NO) or allocated by the order of their device numbers in ascending order (ADDRSORT=YES (the default)). In a multi-cluster grid environment today, customers may have used ADDRSORT=NO to distribute their work load across multiple clusters in the grid by defining each device individually and alternating devices across the clusters. With the allocation assist support enabled, since the goal is to direct allocation requests to specific distributed libraries “clusters” in the grid, ADDRSORT=NO should no longer be needed. Within a distributed library (or cluster) it doesn’t matter which device is used and the main purpose of the allocation assist support is to direct the allocation request to appropriate distributed libraries.
SETNAME Statements:
For the 3490E devices in “composite library 12345, distributed library (10001)"
```
SETNAME,XTYPE=DLB10001,NAMES=(LDGW3495,LDG12345,LDG3490E,LDE12345,LDX10001)
```
For the 3490E devices in “composite library 12345, distributed library (10002)"
```
SETNAME,XTYPE=DLB10002,NAMES=(LDGW3495,LDG12345,LDG3490E,LDE12345,LDX10002)
```

High Watermark Statements:

HWSNAME,TYPE=(LDGW3495,LDG12345,LDG3490E,LDE12345,LDX10001,LDX10002)
   HWSNAME,TYPE=(LDG12345,LDE12345,LDG3490E,LDX10001,LDX10002)
   HWSNAME,TYPE=(LDE12345,LDG12345,LDG3490E,LDX10001,LDX10002)
   HWSNAME,TYPE=(LDG3490E,LDE12345,LDG12345,LDX10001,LDX10002)
   HWSNAME,TYPE=(LDX10001)
   HWSNAME,TYPE=(LDX10002)

Note: The “DLB10001” and DLB10002” device statement names are used here for illustration purposes. When defining the device statement names, any name (up to 8 characters) can be used.