Carefully plan ahead when you assign or remove PCIe endpoint devices to avoid root domain downtime. The reboot of the root domain not only affects the services that are available on the root domain itself but also the I/O domains that have PCIe endpoint devices assigned. Though the changes to each I/O domain do not affect the other domains, planning ahead helps to minimize the consequences on the services that are provided by that domain.
When in a delayed reconfiguration, you can continue to add or remove more devices and then reboot the root domain only one time to make all the changes take effect.
For an example, see How to Create an I/O Domain by Assigning a PCIe Endpoint Device.
Understand and record your system hardware configuration.
Specifically, record information about the part numbers and other details of the PCIe cards in the system.
Use the ldm list-io -l and prtdiag -v commands to obtain the information and save it for future reference.
Determine which PCIe endpoint devices are required to be in the primary domain.
For example, determine the PCIe endpoint devices that provide access to the following:
Boot disk device
Other devices that the primary domain offers as services
Remove all PCIe endpoint devices that you might use in I/O domains.
This step helps you to avoid performing subsequent reboot operations on the root domain, because reboots affect I/O domains.
Use the ldm remove-io command to remove the PCIe endpoint devices. Use pseudonyms rather than device paths to specify the devices to the remove-io and add-io subcommands.
Save this SP configuration to the service processor (SP).
Use the ldm add-spconfig command.
Reboot the root domain to release the PCIe endpoint devices that you removed in Step 3.
Confirm that the PCIe endpoint devices you removed are no longer assigned to the root domain.
Use the ldm list-io -l command to verify that the devices you removed appear as SUNW,assigned-device in the output.
Assign an available PCIe endpoint device to a guest domain to provide direct access to the physical device.
After you make this assignment, you can no longer migrate the guest domain to another physical system by means of the domain migration feature.
Add a PCIe endpoint device to or remove one from a guest domain.
Use the ldm add-io command.
Minimize the changes to I/O domains by reducing the reboot operations and by avoiding downtime of services offered by that domain.
(Optional) Make changes to the PCIe hardware.