Decreasing the CPU and Memory Resources From the Control Domain's Initial factory-default Configuration

You can use CPU DR to decrease the number of the control domain's cores from an initial factory-default configuration. However, you must use a delayed reconfiguration instead of a memory DR to decrease the control domain's memory.

When in the factory-default configuration, the control domain owns all of the host system's memory. The memory DR feature is not well suited for this purpose because an active domain is not guaranteed to add or, more typically, give up, all of the requested memory. Rather, the OS running in that domain makes a best effort to fulfill the request. In addition, memory removal can be a long-running operation. These issues are amplified when large memory operations are involved, as is the case for the initial decrease of the control domain's memory.

Note:

When the Oracle Solaris OS is installed on a ZFS file system, it automatically sizes and creates swap and dump areas as ZFS volumes in the ZFS root pool based on the amount of physical memory that is present. If you change the domain's memory allocation, it might alter the recommended size of these volumes. The allocations might be larger than needed after reducing control domain memory. Before you free disk space, you can optionally change the swap and dump space. See Managing ZFS Swap and Dump Devices in Managing ZFS File Systems in Oracle Solaris 11.4.