A system that runs the Oracle VM Server for SPARC software is able to configure resources, such as virtual CPUs, virtual I/O devices, cryptographic units, and memory. Some resources can be configured dynamically on a running domain, while others must be configured on a stopped domain. If a resource cannot be dynamically configured on the control domain, you must first initiate a delayed reconfiguration. The delayed reconfiguration postpones the configuration activities until after the control domain has been rebooted.
Dynamic reconfiguration (DR) enables resources to be added or removed while the operating system (OS) is running. The capability to perform DR of a particular resource type is dependent on having support in the OS running in the logical domain.
Dynamic reconfiguration is supported for the following resources:
Virtual CPUs – Supported in all versions of the Oracle Solaris 10 OS and the Oracle Solaris 11 OS
CPU whole cores – See Fully Qualified Oracle Solaris OS Versions in Oracle VM Server for SPARC 3.5 Installation Guide
Virtual I/O devices – Supported in at least the Oracle Solaris 10 10/08 OS and the Oracle Solaris 11 OS
Cryptographic units – Supported in at least the Oracle Solaris 10 1/13 OS and the Oracle Solaris 11 OS
Memory – See Using Memory Dynamic Reconfiguration
Physical I/O devices – Not supported
To use the DR capability, the Logical Domains DR daemon, drd, must be running in the domain that you want to change. See the drd(1M) man page.
In contrast to DR operations that take place immediately, delayed reconfiguration operations take effect in the following circumstances:
After the next reboot of the OS
After a stop and start of a logical domain if no OS is running
In general, delayed reconfiguration operations are restricted to the control domain. For all other domains, you must stop the domain to modify the configuration unless the resource can be dynamically reconfigured.
Delayed reconfiguration operations are restricted to the control domain. You can run a limited number of commands while a delayed reconfiguration on the root domain is in progress to support operations that cannot be completed dynamically. These subcommands are add-io, set-io, remove-io, create-vf, and destroy-vf. You can also run the ldm start-reconf command on the root domain. For all other domains, you must stop the domain to modify the configuration unless the resource can be dynamically reconfigured.
While a delayed reconfiguration is in progress, other reconfiguration requests for that domain are deferred until it is rebooted or stopped and started.
The ldm cancel-reconf command cancels delayed reconfiguration operations on the domain. For more information about how to use the delayed reconfiguration feature, see the ldm(1M) man page.
You can use delayed reconfiguration to decrease resources on the control domain. To remove a large number of CPUs from the control domain, see Removing a Large Number of CPUs From a Domain Might Fail. To remove large amounts of memory from the control domain, see Decrease the Control Domain's Memory.
Do not attempt to perform more than one CPU configuration operation on the primary domain while it is in a delayed reconfiguration. If you attempt more CPU configuration requests, they will be rejected.
Workaround: Perform one of the following actions:
Cancel the delayed reconfiguration, start another one, and request the configuration changes that were lost from the previous delayed reconfiguration.
Reboot the control domain with the incorrect CPU count and then make the allocation corrections after the domain reboots.