Conforming to the OVM for SPARC Hard Partition Licensing

Reference:
CPU Cores and CPU Threads
The Oracle VM Server for SPARC software runs on Oracle’s SPARC T-Series servers, which
use SPARC T-Series processors. The SPARC T-Series processors have multiple CPU cores,
and each CPU core has multiple CPU threads. By default, domains that are created with the
Oracle VM Server for SPARC software are configured with CPU threads.
Hard Partitioning and CPU Whole Cores
Beginning with the Oracle VM Server for SPARC 2.0 release, hard partitioning is enforced by
using CPU whole-core configurations. In such a case, domains are configured with CPU whole
cores, instead of the default of individual CPU threads (virtual CPUs). When binding such a
domain, the system provisions the specified number of CPU cores and all its CPU threads to
the domain. Using a CPU whole-core configuration also limits the number of CPU cores that
can be dynamically assigned to a bound or active domain.
Oracle Hard Partition Licensing
To conform to the Oracle hard partition licensing requirement, you must use Oracle VM Server
for SPARC 2.0 or later releases and must use CPU whole cores as follows:
 If a domain runs applications using Oracle hard partition licensing, that domain must
be configured with CPU whole cores.
 If a domain does not run applications using Oracle hard partition licensing, that domain
need not be configured with CPU whole cores. For example, if you do not run any
Oracle applications in the control domain, that domain need not be configured with
CPU whole cores.
Determine whether the domain is configured with CPU whole cores.
# ldm list -o resmgmt domain
 
Verify that the whole-core constraint appears in the output and that the max-cores
keyword specifies the maximum number of CPU cores configured for the domain.
EXAMPLE – Checking Whether a Domain is Configured With CPU Whole Cores
The following command shows that domain ldg1 is configured with CPU whole cores and a
maximum of five cores:
# ldm list -o resmgmt ldg1
NAME
ldg1
CONSTRAINT
   whole-core
         max-cores=5
To List the CPU Cores That Are Assigned to a Domain
# ldm list -o core domain
Example:
# ldm list -o core ldg1
NAME
ldg1
CORE
CID PCPUSET
1 (8, 9, 10, 11, 12, 13, 14, 15)
2 (16, 17, 18, 19, 20, 21, 22, 23)
 
Configuring a Domain With CPU Whole Cores
Use the following command to configure a domain to use CPU whole cores:
# This command also specifies the maximum number of CPU cores for the domain
ldm set-vcpu -c number-of-cpu-cores domain
To Create a New Domain With CPU Whole Cores
1. Create the domain.
# ldm create domain
2. Set the number of CPU whole cores for the domain.
# ldm set-vcpu -c number-of-cpu-cores domain
This command also sets the maximum number of CPU cores for domain to number-of-cpu-cores.
3. Configure the domain.
During this configuration, do not use the ldm add-vcpu, ldm set-vcpu or ldm
rm-vcpu commands without the -c option. If you do so, the domain is reconfigured with
individual CPU threads instead of CPU whole cores.
4. Bind and start the domain.
# ldm bind domain
# ldm start domain
EXAMPLE – Creating a New Domain With 2 CPU Whole Cores
# ldm create ldg1
# ldm set-vcpu -c 2 ldg1
# ldm bind ldg1
# ldm start ldg1
 
To Configure an Existing Domain With CPU Whole Cores
# ldm stop domain
# ldm unbind domain
# ldm set-vcpu -c number-of-cpu-cores domain
# ldm bind domain
# ldm start domain
 
To Configure the Primary Domain With CPU Whole Cores
# ldm start-reconf primary
# ldm set-vcpu -c number-of-cpu-cores  primary
Reboot the primary domain
CPU Dynamic Resource Management
If Dynamic Resource Management (DRM) is used to automatically manage CPU resources on some
domains, DRM policies will not apply to those domains that are configured with CPU whole cores.
Domain Reboot or Rebind
A domain that is configured with CPU whole cores remains configured with CPU whole cores when it
is restarted, or if the entire platform is restarted. A domain uses the same physical CPU cores for the
entire time it remains bound.
Domain Migration

CPU whole-core configuration is incompatible with domain migration. However, you can still migrate

a domain that is configured with CPU whole cores. After such a migration, hard partitioning is not
enforced on the target system. Also, the whole-core configuration and the maximum number of CPU
cores are not preserved by the migration on the target system.

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