Virtual Machine Recommendations and Limits

Virtual machines (VMs) require certain CPU core resources. In addition, only some models of dual-node systems allow both High Availability (HA) and Fault Tolerant (FT) operation, while others allow only HA operation. Single-node systems do not allow HA or FT operation.

Systems and HA or FT Operation

System Model	HA Operation	FT Operation
100i	Yes	No
110i	Yes	Yes
200i	Yes	No
250i	Yes	Yes

For more information, see Modes of Operation.

Recommended Number of CPU Cores

Stratus recommends using only as many threads for workloads as physical threads on a ztC Edge system. The number of threads per system are as follows:

ztC Edge System Model	Total Number of Physical Threads
100i	8
110i	12
200i	12
250i	20

The number of cores recommended for ztC Edge workloads depends upon the number of vCPUs in each VM and the types of the VMs, as described below:

Examples

The following examples apply to dual-node ztC Edge 100i and 200i systems:

Four 2-vCPU HA guests typically require 8 threads, total.
Two 3-vCPU HA guests and one 2-vCPU HA guest typically require 8 threads, total.
Two 4-vCPU HA guests typically require 8 threads, total.
One 8-vCPU HA guest typically requires 8 threads, total.

The following examples apply to dual-node ztC Edge 110i systems and 250i systems, in addition to the examples above:

One 4-vCPU FT guest typically requires 6 threads, total.
Six 2-vCPU HA guests typically require 12 threads, total.
One 2-vCPU FT guest requires 4 threads and two 2-vCPU HA guests require 4 threads, for 8 threads, total.

On a single-node system, each vCPU counts as one thread. The following examples apply to single-node ztC Edge 100i and 200i systems:

Four 2-vCPU guests typically require 8 threads, total.
Two 3-vCPU guests and one 2-vCPU guest typically require 8 threads, total.
Two 4-vCPU guests typically require 8 threads, total.
One 8-vCPU guest typically requires 8 threads, total.

The following example applies to single-node ztC Edge 110i systems and 250i systems, in addition to the examples above: six 2-vCPU guests typically require 12 threads, total.