What is required to enable/disable Dynamic Reconfiguration (DR) for 
each Solaris release?

The following identify the appropriate parameters to enable or disable DR
in the identified releases of Solaris. 

- Solaris 7 - 
+ Parameter: dr-max-mem
Value: Obsolete
Description: 
Resources (cpu, memory, I/O) can always be added (DR attach) 
regardless of the value of dr-max-mem

+ Parameter: kernel_cage_enable*
Value: 0 
Description:
Default. DR detach operations disabled

Value: 1
Description:
Activates the caged kernel and allows DR detach operations

*kernel_cage_enable is set in the /etc/system file.

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- Solaris 2.6 - 
+ Parameter: dr-max-mem
Value: 0
Description:
DR attach/detach is disabled

Value: 1,non-zero
Description:
DR attach/detach is enabled

Value:  2
Description:
In large configurations, particularly those with TBs of storage, 
it is possible during boot to exhaust kernel resources before 
the VM system is fully active. Setting dr-max-mem=2 makes the 
number of DR kernel pages at boot time 5 times larger than the 
normal value. See Bug ID 4218687 for details.

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- Solaris 2.5.1 -
+ Parameter: dr-max-mem
Value: 0
Description:
DR attach/detach is disabled

Value: non-zero
Description: 
DR attach/detach is enabled. The value specifies the largest 
memory configuration permitted for the domain after all DR 
attaches have been completed. For example, a value of 16384 
would allow a maximum of 16GB of memory for a domain 
(i.e. 4 fully loaded system boards). But setting the value 
unnecessarily large bloats the kernel and wastes memory that 
might otherwise be used more productively.