Here are the top KVM questions we get on Oracle Database Appliance. Let us know in the comments section if you have any other questions. Check this blog entry frequently as new information will be added.
Oracle Database Appliance - Product Management Team
General KVM Questions:
Q: What’s the difference between application KVM and database KVM (a.k.a. DB System) in ODA?
Application KVM: Customers use the integrated ODA command line (ODACLI) or Browser User Interface (BUI) to manage (create, modify and delete) the application KVM. Customers are responsible for deploying and maintaining the application inside the KVM.
Database KVM: Customers use the integrated ODACLI or BUI to manage the database KVM and to deploy and maintain the database inside the database KVM
Q: Does ODA HA system provide high availability for application and database KVMs?
A: Yes. Customers can create application KVMs with auto-restart or auto-failover enabled. Oracle DB System Enterprise Edition (EE) can be protected by RAC or RAC One for failover, and Oracle DB System Standard Edition (SE) is protected by Standard Edition High Availability (SEHA) feature.
Q: Does ODA support KVM live migration?
Q: Why does ODA use KVM instead of Containers?
A: KVM provides more isolation and is the virtualization technology used in Oracle Cloud Infrastructure (OCI).
Q: Is there a KVM monitoring tool for resource usage (CPU, disk I/O, network I/O) like Linux KVM virt-manager?
A: Not at this time. Customers can continue to use virt-manager to monitor resources.
Q: How does a user back up application and database KVMs?
A: For ODA 19.10 application KVMs, backup the KVM ACFS files. For ODA 19.10 DB Systems, backup the database using the standard database backup tools (e.g., RMAN).
Q: How do customers migrate databases from ODA-OVM to ODA-KVM?
A: Currently, the ODA-KVM only supports Oracle Database 19.10. Once different Oracle Database versions (DB System) are supported, it is required to re-image the customer’s ODA-OVM system to ODA Bare-Metal with 19.10 or newer. Customers may use various methods to migrate their database from OVM to KVM (export/import, Data Guard, etc.).
Q: How do customers migrate applications from ODA-OVM to ODA-KVM?
A: Customers would need to reinstall the application in ODA-KVM. We are looking at potential tool to export guest-ODA-OVM and import it into ODA-KVM.
Q: Can a user use a third-party tool to import vmware.ova image into ODA KVM?
A: This has not been tested by Oracle.
General DB System (database KVM) Questions:
Q: What Oracle database version is supported in the DB System?
A: With ODA 19.10, only Oracle 19.10 database is supported in DB System. The supported database version for a given DB System version can be queried using odacli describe-dbsystem-image.
Q: How many databases does a DB System support?
A: One database per DB System. It can be CDB or non-CDB. It's recommended for users who want to have multiple databases per DB System to consolidate into a CDB.
Q: What is the minimum size of a DB System?
A: The minimum CPU cores a DB System supports are two cores. With 19.10, if a smaller database shape with 1 CPU core is selected, the DB System will ignore that and be configured with a minimum of 2 CPU cores and 16GB RAM.
Q: Can a user use both DB system and bare-metal databases?
A: Yes. But the user will need to license Oracle databases based on the bare-metal license rules.
Q: How many cores does a DB System use?
A: The shape of the DB System is derived from the shape a user selects for the database. For example, if a customer selects odb4 as the database shape, in which the database uses 4 cores, then the DB System is created with 4 cores. For database shapes odb1s and odb1, a 2-core DB System will be created.
Q: Can a user create a database on ACFS or use ACFS inside a DB System?
A: The database datafiles in the DB System are on ODA ASM Storage. A user cannot create a database on ACFS inside the DB System. The DB System storage (Oracle Database and GI homes) is on ODA ACFS file system.
Q: Does DB System support oversubscription?
A: No, each DB System is associated with a CPU pool created internally. In ODA 19.10, the CPU pool associated with a DB System cannot be shared.
Q: What is the maximum number of DB Systems that can be created in an ODA system?
A: It depends on the CPU cores and the ODA system’s memory (i.e., ODA X8-2M has a maximum of 32 cores for both application KVM and DB Systems). Also, by default, half of the ODA memory is allocated to HugePages, and the DB System memory uses HugePages. Users must plan accordingly.
Q: How does a DB System use the storage?
A: The DB System’s local file system includes the /u01 (GI and database homes), boot partition, /partition for the OS, swap space and /opt partition for the ODA software. The DB System local file system size is fixed at 200GB per node, and it is on ACFS.
DB System database storage is on an ASM diskgroup. There is no quota limit per database.
Q: Can multiple DB Systems be created at the same time?
A: DB Systems that use different diskgroups (i.e., DATA, RECO) as its VM storage can be created at the same time. If they are using the same diskgroup as VM storage, they need to be created sequentially.
Q: Can the FLASH diskgroup be used for DB System VM storage?
A: No. Currently, only DATA and RECO diskgroups can be used for DB System VM storage.
Q: Is the DB System name case sensitive?
A: No, it is not case sensitive. A DB System named "DBSystem1" is the same as "dbsystem1”.
Q: Does ODA database KVM (DB System) support hard partitioning for Oracle Database license?
Q: Is ODA database KVM (DB System) considered an “Oracle Trusted Partition”?
A: Not at this time. Oracle Trusted Partitioning requires live migration and other conditions that ODA does not currently support.
Q: Can the CPU pool feature be used for hard partitioning licensing?
A: No. The CPU pool is only for resource management.
Q: How do I determine the number of cores that need to be licensed for Oracle Database with ODA DB Systems?
A: The number of cores that need to be licensed is determined by the database shape selected (the minimum is two cores) per DB System. If you have multiple DB Systems, you need to license the total number of cores used in all the DB Systems.
Q: In an ODA HA system, can you license different core quantities per node?
A: Yes. You can have both single instance and RAC databases (DB Systems) on both nodes; therefore, the number of cores used per node may differ.
Q: Can a user run both EE and SE databases in KVMs on one ODA system?
A: Yes, but the customer is responsible for ensuring that all SE databases are running in one socket via CPU pool(s) as Oracle SE license is socket-based. On an ODA HA system, a customer can run single instance EE databases on one node and SE databases on the second node. However, no failover (RAC or SEHA) is allowed from licensing perspective.
Q: Can a user mix both Oracle EE and Named User Plus (NUP) in KVMs on one ODA system?
A: Yes. Both EE and NUP are processor-core-based licenses.
Q: What are the licensing rules for application KVM in ODA?
A: Check with the application vendor