PPRC ( peer - to - peer remote copy ) connections are direct connections between DASD controller subsystems that are used primarily to provide a hot standby capability. These connections can be point-to-point from one DASD controller to another, or they may pass through switches, just as connections from CHPIDs to control units can. Note that HCM provides methods to physically document PPRC connections, and to export PPRC connection information into CESTPATH command and GEOPARM control statement format for further use on the host. HCM does not validate whether the entered PPRC links are valid links in a real configuration, but HCM only provides documentation for this type of connections. In this scenario, we will set up a PPRC connection that consists of several single PPRC links. To demonstrate what you can do with this utility, some of the PPRC links will directly connect two subsystems with each other, while other PPRC links involve a director . Let us consider a basic configuration where we have the following I/O objects already defined:
- A FICON director, type 2032, Id =05
- An IBM Enterprise Storage Server® (ESS)
DASD subsystem #1, consisting of control units 3000 and 3010, both
having SSID 3000 specified, that has connections as follows:
- Interface 04.A[0C] connected to director 05.40
- Interface 04.B[0D] connected to director 05.41
- A second IBM Enterprise Storage
Server (ESS) DASD subsystem #2, consisting of control units 4000
and 4010, both having SSID 4000 specified, that has connections as
follows:
- Interface 04.A[0C] connected to director 05.50
- Interface 04.B[0D] connected to director 05.51
- Devices of type 3390 which are connected to the control units as follows: device range 3000,32 connected to control units 3000 and 3010, and device range 4000,32 connected to control units 4000 and 4010
To establish a PPRC connection, proceed as follows:
- Edit the subsystem #1 by either selecting Edit:Controller and choosing the controller from the list or by double-clicking on the controller in the diagram. This opens the Controller dialog.
- Select interface 12.A[8C] and click Connect. This opens the Select Connection Target(s) dialog.
- Choose interface 12.A[8C] of DASD subsystem #2 as target, and click Physical only to connect both interfaces.
- Repeat steps 2 and 3, now connecting the interfaces 12.B[8D] of both DASD subsystems #1 and #2 with each other. Click Close to leave the Controller dialog.
- Select Create: PPRC Connection. This opens the Create PPRC Connection dialog. This utility guides you through 4 pages on which you can specify certain information needed to create a PPRC connection.
- Click on the first entry of the list (SSID 3000) in order to
select the primary (source) subsystem of the PPRC connection, and
click Next. This will show page two of the Create PPRC
Connection dialog. Figure 1. Create PPRC Connection (1)
- Click on the second entry of the list (SSID 4000) in order to select the secondary (target) subsystem of the PPRC connection, and click again Next which will lead you to page 3 of the utility.
- We want to create a PPRC connection consisting of four single
PPRC links. Therefore, click the More button three times to
obtain altogether 4 possible entries for a source and a target interface.
As source interfaces on the left side of the dialog, select the interfaces
4.A[0C], 4.B[0D], 12.A[8C], 12.B[8D] which are interfaces of the DASD
subsystem #1. As the latter two interfaces are directly connected
to interfaces of DASD subsystem #2, HCM automatically fills the entries
on the right side (target interfaces). Your Create PPRC Connection dialog
should now look similar to the following: Figure 2. Create PPRC Connection (2)
Select the target interfaces 4.A[0C] and 4.B[0D] of DASD subsystem #2 to finish specifying the interfaces for both the source and the target subsystem.
Figure 3. Create PPRC Connection (3)
Click Next which will show the last page of the utility.
- Specify the parameters as needed, and finally click Finish to
complete setting up the PPRC connection. Figure 4. Create PPRC Connection (4)
You have now defined a new PPRC connection consisting of 4 single PPRC links. Using Locate:PPRC Connection, you can locate and highlight the PPRC connection in the diagram at any time.