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15.2 Changing the Memory Configuration


15.2 Changing the Memory Configuration
This section describes how to change the memory configuration by using the dynamic reconfiguration (DR) function of Oracle VM Server for SPARC.
Note - To dynamically change logical domain resources, the Logical Domain Dynamic Reconfiguration (drd) daemon must be running on the target domain.
On the SPARC M12/M10 systems, various business processes run on each logical domain. The memory configuration can be flexibly changed according to the system operation status. In some active processes, load is concentrated into a given logical domain, so performance with only the configured memory used can be considered to be lower. In such a situation, the logical domains in the same physical partition can be reallocated. This is done by dynamically assigning the memory of domains that have a relatively low load.

The memory configuration can be changed in units of 256 MB.

To change the memory configuration, first use the ldm remove-memory command of Oracle VM Server for SPARC to delete memory from logical domains that have a relatively low load. Then, use the ldm add-memory command of Oracle VM Server for SPARC to add memory to logical domains that present concerns about lower performance due to increased load.
Deleting Memory
primary# ldm remove-memory size[unit] ldom
For size, specify the size of the memory to delete. For unit, specify the unit of memory. For ldom, specify the logical domain from which to delete the memory.

Adding Memory
primary# ldm add-memory size[unit] ldom
For size, specify the size of memory to add. For unit, specify the unit of memory. For ldom, specify the logical domain to which to add the memory.
Operation Procedure
  1. Switch from the XSCF console to the control domain console to which the target logical domain belongs.
    For details on how to switch to the control domain console, see "8.3 Switching to the Control Domain Console From the XSCF Shell."
  2. Check the memory capacity of each domain with the ldm list-domain command.
    The following example checks the status of the primary, ldom1, ldom2, and ldom3 logical domains.
primary# ldm list-domain
NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME
primary active -n-cv- SP 8 4G 3.1% 1d 36m
ldom1 active -n---- 5001 16 2G 34% 1m
ldom2 active -n---- 5002 16 1G 34% 17h 48m
ldom3 active -n---- 5003 24 4G 17% 17h 48m
  1. Delete memory from a domain with the ldm remove-memory command.
    The following example deletes 1 GB of memory from ldom3.
primary# ldm remove-memory 1G ldom3
  1. Add memory to a domain with the ldm add-memory command.
    The following example adds 1 GB of memory to ldom1.
primary# ldm add-memory 1G ldom1
  1. Check for a configuration change in the memory capacity of each domain with the ldm list-domain command.
    In the following example, check for configuration changes in the primary, ldom1, ldom2, and ldom3 logical domains.
primary# ldm list-domain
NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME
primary active -n-cv- SP 8 4G 3.1% 1d 36m
ldom1 active -n---- 5001 16 3G 34% 1m
ldom2 active -n---- 5002 16 1G 34% 17h 48m
ldom3 active -n---- 5003 16 3G 17% 17h 48m
  1. You can see that memory has been deleted from the domain ldom3 and added to ldom1.
  2. Log out from the control domain console to return to the XSCF console.
    For details on how to return to the XSCF console from the control domain console, see "8.4 Returning to the XSCF Shell From the Control Domain Console."