To control whether a system board contains kernel memory, use one or more of the following features, which are described below: kernel cage, floating boards, and kernel memory assginment.

To copy kernel memory from one board to another, use the Copy-rename operation. Copy-rename makes it possible for you to perform DR operations on kernel memory boards.

(1.1) Kernel Cage

The kernel cage function must be in use for DR operations on memory to succeed. Without the kernel cage, kernel memory could be assigned to all system boards, making it impossible to perform DR operations on memory. With the kernel cage, kernel memory is limited to a minimum set of system boards.

For details on enabling this function, see Section 2.3.2, “Settings of Kernel Cage Memory” on page 2-16.

(1.2) Floating Boards

A floating board is a system board that is designated to be moved easily to another domain. In general, kernel memory is not assigned to a floating board unless absolutely necessary.

However, kernel memory can be assigned to a floating board when one of the following is true:

The total amount of space available among non-floating boards is not enough to hold the kernel memory.

The deleteboard(8) command is used with its -f(force) option.

For details on enabling the floating board option for a system board, see

Section 2.2.2.2, “Floating Board Option” on page 2-14. Also see the SPARC Enterprise M4000/M5000/M8000/M9000 Servers XSCF User’s Guide or the setdcl(8) man page for further details.

(1.3) Kernel Memory Assignment

When a domain is powered on, the Power On Self Test (POST) initially assigns an address space to each system board in that domain. The order in which address spaces are assigned depends on the LSB number and floating board option of each system board. The first address spaces are assigned to non-floating boards in ascending order of LSB number. Then, additional address spaces are assigned to floating boards, again in ascending order of their LSB numbers.

2-6SPARC Enterprise Mx000 Servers Dynamic Reconfiguration User’s Guide • September 2007