Factors to Consider While Selecting Hardware for Oracle VM

While choosing hardware for Oracle VM environments, many factors have to be considered in order to choose the best hardware architecture to make your Oracle Cloud project a success. The important factors to consider are the Oracle VM Server CPU, RAM and storage requirements; you will also need to consider hardware vendor certification, type of internal hard drives, etc.

Vendor certification
The server hardware must be jointly supported by the hardware vendor and Oracle. Only jointly supported hardware product receives vendor support when problems occur and service tickets are created.

Server hardware will be ordered with two socket Intel or AMD multiple-core CPUs for small and medium workloads and four socket multiple-core CPUs for large CPU-bound workloads. The maximum number of CPU cores or threads an Oracle VM server can support is 160. Oracle VM server maps a virtual CPU to a hardware thread on a CPU core in a CPU socket. Oracle VM Server supports CPU over-subscription, which means that an Oracle VM Server with 160 CPU cores could over-allocate the total number of CPU cores to virtual machines. For example, a server with an Intel Xeon processor 5600-series CPU with hyper-threading can have up to six cores and twelve threads per socket. A two socket server with an Intel Xeon processor 5600-series CPU could allocate twenty four virtual CPUs without oversubscribing the physical CPUs. CPU-bound workloads should not be on servers with oversubscribed CPUs.

Server hardware will be ordered with the maximum amount of physical memory. Oracle VM server does not support memory over-subscription, which means that an Oracle VM server cannot accept a Live Migration or HA request unless the server has available RAM for the virtual machines. Having available RAM on each server provides flexibility in terms of adding new virtual machines to the server pool, and to allow Live Migration and HA within a server pool. By default, each Oracle VM server reserves 512 MB of memory for dom0. The average memory overhead for each running guest on a dom0 is approximately 20 MB plus 1% of the guest’s memory size. The remaining physical memory can be allocated to guests.

Unless the Oracle VM server is booting from SAN, an SSD internal hard drive is recommended. Virtual machine image and configuration files are hosted on shared SAN, iSCSI, or NFS repositories. Oracle VM Server requires “only” 4 GB of local storage for the entire Oracle VM Server installation. The design goal for Oracle VM is to support multiple node Oracle VM Server pools with shared fibre channel SAN, iSCSI and/or NFS storage.

Network Interface Cards
For network-interface high availability 802.3AD bonds are used for each pair of network interfaces. Oracle VM supports two NICs ports per 802.3 AD bond and a total of five 802.3AD bonds per Oracle VM Server. Both 802.3AD NIC bonds, port-based VLANs and/or 802.1Q tag-based VLANs are supported and configured post Oracle VM Server installation with Oracle VM Manager. Network redundancy, i.e. 802.3AD NIC bonding doubles the number of required NICs. Oracle VM uses a total of five discrete networks – Server Management, Cluster Heartbeat, live Migration, Storage and Virtual Machines. All five networks can be supported using one mode 2 bond with 802.1Q tag-based VLANs (2 NICs) or using up to five 802.3AD bond (10 NICs).

Host Bus Adapter Cards
For your storage area network, you will require 2 Host Bus Adapter Cards (HBAs) with minimum of 4 GFC. Using 2 HBAs eliminate any single point of failure. The HBA card can be chosen up to 20 GFC based on the line-rate and throughput capacity required for the network.

By following the above guidelines, you will be able to set up Oracle VM environment with the right hardware architecture.