Configuration limits for Oracle VM represent tested and recommended limits, and are fully supported by Oracle.
Table 7.1 Server Pool and Cluster Maximums
Item | x86 Maximum | SPARC Maximum |
|---|---|---|
Oracle VM Servers in a server pool (unclustered) | 64 | 64 |
Oracle VM Servers in a server pool (clustered) | 32 | 32 |
Number of servers | 256 (16 servers * 16 server pools) | 256 (16 servers * 16 server pools) |
Number of server pools | 16 | 16 |
Number of configured virtual machines | 5120 (20 virtual machines * 256 servers) | 5120 (20 virtual machines * 256 servers) |
Number of running virtual machines | 2,560 (10 virtual machines per server * 256 servers) | 32768 (128 virtual machines per server * 256 servers)
|
Some performance tuning is required in Oracle VM environments where you manage more than 80 instances of Oracle VM Server with a single instance of Oracle VM Manager. In these environments, you should increase JVM memory allocation to 8G and reduce the interval of statistics collection. See the following topics for more information:
Oracle Support can apply additional tuning configurations to optimize Oracle VM Manager performance, such as reducing the number of events that Oracle VM Manager processes. Contact Oracle Support for more information.
Table 7.2 Oracle VM Server Maximums
Item | x86 Maximum | SPARC Maximum |
|---|---|---|
CPUs | 384 (Tested) 2048 (Designed) | Equivalent to the number of available CPUs.
|
Virtual CPUs per host | 4096 | 8 per core on Oracle M-series and Oracle T-series servers
2 per core on Fujitsu M10
|
RAM | 6 TB | Equivalent to available RAM.
A small amount of RAM is required for the hypervisor. |
Concurrently Running Virtual Machines | 1024 The maximum number of concurrently running virtual machines depends on the virtual machine configuration, hardware resources, and workloads the virtual machines are running. For this reason, the practical limit for concurrently running virtual machines is 300. | 128 per physical domain (PDOM) SPARC M5 or M6-series server each have a maximum of 512 logical domains (128 logical domains per physical domain * 4 physical domains). However, when following Oracle best practices that allocate full cores for guests, the maximum number of logical domains is 192 on SPARC M5-series servers and 384 on SPARC M6-series servers. |
By default, when you install Oracle VM Server, dom0 is configured with a maximum of 20 vCPUs. This configuration optimizes performance for large systems and is suitable for most deployments.
If you plan to change the number of maximum vCPUs for dom0, Oracle Corporation recommends that you set the number of vCPUs for dom0 to no greater than the number of physical CPUs per socket. Oracle Corporation also recommends that you pin dom0 vCPUs to physical CPUs on the first socket. If you use hyper-threading, you should count in units of threads instead of cores. For more information see Editing Boot Parameters To Enable Hypervisor Features in the Oracle VM Installation and Upgrade Guide.
For information on performance optimization goals and techniques for Oracle VM Server for x86, see Optimizing Oracle VM Server for x86 Performance, on Oracle Technology Network at: http://www.oracle.com/technetwork/server-storage/vm/ovm-performance-2995164.pdf.
Table 7.3 Virtual Machine Maximums
Item | x86 Maximum | SPARC Maximum |
|---|---|---|
Virtual CPUs | PVM: 256 HVM: 128; or 32 for Microsoft Windows guests. PVHVM: 128; or 32 if using Oracle VM Paravirtual Drivers for Microsoft Windows. | Equivalent to the number of available CPUs on the server.
These maximums do not account for CPUs allocated to any other domains, such as the control domain. The hypervisor can allocate subsets of the overall CPU, memory, and I/O resources of a server to any given logical domain. |
Virtual RAM on 32-bit guests | PVM: 64 GB HVM: 64 GB PVHVM: 64 GB | N/A |
Virtual RAM on 64-bit guests | PVM: 500,000 MB Note The amount of memory supported is dependent on the guest kernel. Oracle has tested 470GB with Oracle VM Release 3.4.2.
HVM: 1,000,000 MB Exceeding the 1 TB limit may work, but can result in slow boot times and the possibility that the virtual machine hangs at boot and soft lockups occur on the hosting Oracle VM Server. If your environment needs to support live migration for HVM guests, this value must not exceed 1 TB. PVHVM: 2,000,000 MB; or 256 GB if using Oracle VM Paravirtual Drivers for Microsoft Windows Release 3.2.3 and later. | Equivalent to the amount of available RAM installed on the server.
A small amount of RAM is required for the hypervisor. These maximums do not account for RAM that is allocated to any other domains, such as the control domain. The hypervisor can allocate subsets of the overall CPU, memory, and I/O resources of a server to a given logical domain. |
Virtual NICs | PVM: 31 HVM: 8 PVHVM: 8 The limit to the number of virtual disks and virtual NICs is shared when using the Oracle VM Paravirtual Drivers for Microsoft Windows. Therefore, if you define 8 virtual NICs, only 32 virtual disks can be defined for the same virtual machine. | Depends on the total number of available Logical domain channels (LDC). Total number of virtual NICs and virtual disks per domain for SPARC is no more than the total number of available LDCs of the supported SPARC server. For more information, see Using Logical Domain Channels in the Oracle VM Server for SPARC Administration Guide. |
Virtual disks | Limits provided here are imposed by the guest kernel and not the hypervisor. The maximums presented depend on the capabilities of the guest operating system. PVM: 104 HVM: 4 IDE (including CD-ROM), 7 SCSI PVHVM: 107; or 40 if using Oracle VM Paravirtual Drivers for Microsoft Windows Release 3.2.3 and later. The limit to the number of virtual disks and virtual NICs is shared when using the Oracle VM Paravirtual Drivers for Microsoft Windows. Therefore, if you define 8 virtual NICs, only 32 virtual disks can be defined for the same virtual machine. | Depends on the total number of available Logical domain channels (LDC). Total number of virtual NICs and virtual disks per domain for SPARC is no more than the total number of available LDCs of the supported SPARC server. For more information, see Using Logical Domain Channels in the Oracle VM Server for SPARC Administration Guide. |
Virtual disk size | OCFS2: 64 TB NFS: 10 TB | Equivalent to the size of available disks on the server. The Oracle Solaris limit is 263. |
For information on the configuration limits used for the latest Oracle VM Paravirtual Drivers for Microsoft Windows release, see http://docs.oracle.com/cd/E88077_01/index.html.
Virtual machine maximums assume a single virtual machine using all available resources.
Access the Oracle VM Server for SPARC documentation at http://www.oracle.com/technetwork/documentation/vm-sparc-194287.html. To determine the version of the Oracle VM Server for SPARC documentation to reference, run the pkg list ldomsmanager command.
Table 7.4 Storage Maximums
Item | x86 Maximum | SPARC Maximum |
|---|---|---|
LUNs in a storage array This limit should not be confused with multipath devices. Each identical LUN connected to a single multipath device is considered to be a separate LUN with regard to this limit. Examples of supported configurations of iSCSI LUNs:
Examples of supported configurations of Fibre Channel LUNs:
| iSCSI:
Fibre Channel (FC):
| 232 targets. |
OCFS2 volume size | 64 TB | N/A |
Files per OCFS2 volume | 30,000 | N/A |
Table 7.5 Network Maximums
Item | x86 Maximum | SPARC Maximum |
|---|---|---|
NICs/ports per network bond | 256 | 255 per bond or aggregate. |
Network bonds per Oracle VM Server | No limit | No limit |
Number of VLANs | 1024 | 1024 |
Number of MAC addresses | 10240 | 10240 |