Make your hardware switchable

In a multisystem environment, you must make an external expansion unit switchable.

When you are using independent disk pools in a switchable environment, the associated hardware must be authorized to switch as well. Depending on your environment, this can include frame/units or input/output processors (IOPs) and their associated resources. Refer to the following steps that apply to your switchable environment.

Make a frame and unit switchable

An independent disk pool can contain disk units within several expansion units (frame/units). If you have a stand-alone expansion unit that contains disk units included in an independent disk pool, you must authorize the expansion unit to grant access to other servers. This is called making an expansion unit switchable. If you do not want other servers to be able to access the stand-alone expansion unit, you must make the expansion unit private.

To make a frame/unit switchable, follow these steps:
  1. In iSeries™ Navigator, expand My Connections (or your active environment).
  2. Expand any iSeries server.
  3. Expand Configuration and Service > Hardware > Disk UnitsBy Location and select the frame/units you want to make switchable.
  4. Right-click a highlighted frame/unit and select Make Switchable.
  5. Follow the instructions on the dialog box that is displayed.

Change a bus ownership type

To allow an IOP to be switched, the bus containing the IOP that controls the disk units to be switched must be owned shared by the primary node. The bus must also be use bus shared by the backup node. See Dynamically switching IOPs between partitions for more information.

To complete this task, you need a Service Tools user profile with administration authority to the System Partitions function in dedicated service tools (DST). For more information about obtaining logical partition privileges, refer to Logical partition authority.

To change the ownership type for a bus using Management Central, follow these steps:
  1. In iSeries Navigator, expand My Connections.
  2. Select the primary partition of the system.
  3. Expand Configuration and Service and select Logical Partitions.
  4. Right-click the Logical Partition and select Configure Partitions.
  5. In the Configure Logical Partitions window, right-click the bus for which you want to change ownership and select Properties.
  6. Select the Partitions page.
  7. Select the partition that owns the bus in Owning logical partition, and then select the ownership type in Sharing. If the ownership type is shared, the partitions that share the bus appear in the list. Click Help if you need more information about these options.
  8. Click OK.

Create an I/O Pool using the Hardware Management Console

If you are using the Hardware Management Console to manage your logical partitions, you must create an I/O pool that includes the IOP, input/output adapter (IOA), and all attached resources to allow an independent disk pool to be switchable between partitions. You must grant access to each partition that you want to own the independent disk pool by assigning the I/O pool in each partition profile.

To create an I/O pool that can be switched between partitions, follow these steps:
  1. Open the Logical Partition Profile Properties window to change partition profile properties and assign resources to an I/O pool.
  2. Click the Physical I/O tab.
  3. In the Profile I/O devices column, expand the bus that contains the IOP that you want to make switchable.
  4. Select the IOP that you want to assign to an I/O pool. The IOP must be desired (no check mark in the Required column).
  5. Click the I/O Pool column so that the cursor appears in the row of the IOP you want to assign to an I/O Pool, and type the number for the I/O pool.
  6. Repeat these steps to add each IOA and resource under the control of the IOP to the I/O pool.
  7. Click OK.
After you have added the resources to the I/O pool, complete the following steps to associate the I/O pool with each additional partition that you want to be able to own the independent disk pool in the switchable environment.
  1. Open the Logical Partition Profile Properties window to change partition profile properties for each additional partition that needs to access the independent disk pool.
  2. Click the Physical I/O tab.
  3. Click Advanced.
  4. On the I/O Pools window, in the I/O pools to add field, type the number of the I/O pool to which you assigned the resources that you want to switch with the independent disk pool.
  5. Click Add.
  6. Click OK.
For the I/O pool changes to take effect, you must complete the following steps for each partition whose partition profile was changed:
  1. Shut down the partition. See Restarting and shutting down i5/OS™ in a logical partition.
  2. Start the logical partition by activating the partition profile to reflect the changes.
Parent topic: Manage independent disk pools