Attachment Point

Attachment point: a collective term for a board and its card cage slot.

DR can display the status of the slot, the board, and the attachment point. For DR purposes, a board also includes the devices connected to it, so the DR term occupant is used to refer to the combination of board and attached devices.

• A slot (also called a receptacle) may have the ability to electrically isolate the occupant from the host machine. That is, DR software can put a single slot into low-power mode.

• Receptacles can be named according to slot numbers or can be anonymous (for example, a SCSI chain). To obtain a list of all available logical attachment points, use the -l option with the cfgadm command.

• An occupant I/O board includes any external storage devices connected by interface cables.

There are two types of system names for attachment points:

• A physical attachment point describes the software driver and location of the card cage slot. An example of a physical attachment point name is:

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  /devices/central@1f,0/fhc@0,f8800000/clock-board@0,900000:sysctrl,slot0
  

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• A logical attachment point is an abbreviated name created by the system to refer to the physical attachment point:

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  sysctrl0:slot0
  

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Detachability

A board is not detachable if it has a critical resource (such as a boot drive) connected to it. Similarly, if a system has only one CPU board, the CPU board cannot be detached.

For a device to be detachable:

• The device driver must support DDI_DETACH

• Critical resources must be accessible through an alternate pathway

If there is no alternate pathway for an I/O board, you can:

• Put the second disk chain on a separate I/O board. The secondary I/O board can be detached (with a loss of access to the secondary disk chain).

• Add a second path to the device through a second I/O board. The I/O board can be detached (using Alternate Pathing software to switch access through the alternate board) without losing access to the secondary disk chain.