Attachment Points

Attachment points are locations on the system where DR can occur.

An attachment point consists of the following parts:

• Occupant – a hardware component that can be configured into the system. An occupant's state can either be configured or unconfigured.

• Receptacle – the location that accepts the occupant. A receptacle's state can either be connected or disconnected. The empty state also exists but applies only to non SCSI host bus adapters (HBAs).

The following table shows the combined states of occupants and receptacles on attachment points and the corresponding states of a device.

Occupant and Receptacle Combined States Description of Device State Unconfigured/Empty Device is not physically connected (applies to non SCSI HBAs only. Unconfigured/Disconnected Device is logically disconnected and unavailable, even though the device might be physically connected. Unconfigured/Connected Device is logically connected but unavailable. Device is included in the prtconf command output. Configured/Connected Device is connected and available.

About Attachment Point Identification

Attachment points are represented by physical and logical attachment point IDs (Ap_Ids). The physical Ap_Id is the physical path name of the attachment point. The logical Ap_Id is a user-friendly alternative for the physical Ap_Id. For more information on Ap_Ids, refer to cfgadm(1M) man page.

The logical Ap_Id for a device consists of the combination of the HBA Ap_Id and the device identifier, and follows the format HBA-apid::device-identifier.

For example, the Ap_Id of a SCSI HBA is normally the controller number, such as c0. If the device identifier on the HBA is dsk, then that device's logical Ap_Id would be c0::dsk.

The device identifier is derived from the logical device name in the /dev directory. For example, a tape device with logical device name, /dev/rmt/1, would have the device identifier rmt/1. Thus, the tape device's logical Ap_Id would be c0::rmt/1.

If an HBA Ap_Id has no controller number, an internally generated unique identifier is provided, such as fas1:scsi. If a device identifier cannot be derived from the logical name in the /dev directory, then an internally generated unique identifier is also provided. For example, for the /dev/rmt/1 tape device, the logical name might be st4 and the logical Ap_Id would be c0::st4.

For more information about SCSI Ap_Ids, refer to cfgadm_scsi(1M).