DR 2.0 and IDNs

The IDN feature allows domains to communicate to each other over the interconnect by using standard TCP/IP protocols. To provide this capability, the IDN feature maintains detailed information about the hardware configuration and is dependent on the hardware configuration of the member domains.

The DR feature allows the user to reconfigure the hardware while the operating system is running. Thus, DR is required to make an IDN aware of the changes so that the IDN can maintain consistent, up-to-date information about the hardware.

DR accomplishes this requirement by unlinking the domain from the IDN, reconfiguring the hardware, and relinking the domain to the IDN. The unlinking and relinking of the domain occurs during the complete attach or complete detach phase of the DR operation. DR determines whether the domain is a member of an IDN, and it performs the unlinking and relinking of the domain during the complete phase. No interaction is needed by the user. However, if a member domain is in an unknown state (that is, AWOL), the unlink operation will not succeed, especially if the domain is in a non-responsive state. If one or more domains were in an unknown state when you attempted to perform a DR operation, you must unlink all of the AWOL domains within the IDN in a single step (that is, use the domain_unlink(1M) command with all of the names of the AWOL domains).

During the period in which the domain is not linked to the IDN, no transmission to or from the domain are allowed. In contrast, the domain remains a member of the IDN as defined in the domain_config(4) file on the SSP, and the domain continues to be listed as a member of the IDN when you use the domain_status(1M) command.

Due to the interaction between the DR and IDN features, only one DR or IDN operation is allowed at any given time within a single Sun Enterprise 10000 system.

Certain conditions may require you to use the force option. In the context of a DR operation, you can use the DR force option, which is passed to the domain_unlink(1M) command. When used on a domain that is a member of an IDN, the force option should be used with extreme care. Refer to the Sun Enterprise 10000 InterDomain Networks User Guide for more information about the force option and its use.