Hardware Requirements

Enterprise networks can vary in performance, capacity, protocols, and overall activity. Resource requirements to consider for Nessus deployments include raw network speed, the size of the network being monitored, and the configuration of Nessus.

Note: The following recommendations are guidelines for the minimum hardware allocations. Certain types of scans are more resource intensive. If you run complex scans, especially those with credentials, you may require additional disk space, memory, and processing power.

Storage Requirements

You must install Nessus on direct-attached storage (DAS) devices. Nessus does not support storage area networks (SANs) or network-attached storage (NAS) configurations.

Nessus Scanners and Nessus Professional

The following table lists the hardware requirements for Nessus scanners and Nessus Professional.

Scenario	Minimum Recommended Hardware
Scanning up to 50,000 hosts per scan	CPU: 4 2GHz cores Memory: 4 GB RAM (8 GB RAM recommended) Disk space: 30 GB
Scanning more than 50,000 hosts per scan	CPU: 8 2GHz cores Memory: 8 GB RAM (16 GB RAM recommended) Disk space: 30 GB (Additional space may be needed for reporting)

Nessus Manager

The following table lists the hardware requirements for Nessus Manager.

Scenario	Minimum Recommended Hardware
Nessus Manager with 0-10,000 agents	CPU: 4 2GHz cores Memory: 16 GB RAM Disk space: 30 GB (Additional space may be needed for reporting)
Nessus Manager with 10,001-20,000 agents	CPU: 8 2GHz cores Memory: 64 GB RAM Disk space: 30 GB (Additional space may be needed for reporting) Note: Engage with your Tenable representative for large deployments.

Virtual Machine

Nessus can be installed on a Virtual Machine that meets the same requirements. If your virtual machine is using Network Address Translation (NAT) to reach the network, many of the Nessus vulnerability checks, host enumeration, and operating system identification are negatively affected.

Nessus Agents

Nessus Agents are designed to be lightweight and to use only minimal system resources. Generally, a Nessus Agent uses 40 MB of RAM (all pageable). A Nessus Agent uses almost no CPU while idle, but is designed to use up to 100% of CPU when available during jobs.

For more information on Nessus Agent resource usage, see Agent Software Footprint and Agent Host System Utilization.

The following table outlines the minimum recommended hardware for operating a Nessus Agent. Nessus Agents can be installed on a virtual machine that meets the same requirements specified.

Hardware	Minimum Requirement
Processor	1 Dual-core CPU
Processor Speed	< 1 Ghz
RAM	< 1 GB
Disk Space	< 1 GB with normal usage < 2 GB under certain conditions, e.g. when a plugins-code.db defragmentation operation is in progress
Disk Speed	15-50 IOPS