Hardware Requirements

Tenable Agents

Tenable Agents is a lightweight, user space program and only use minimal system resources.

Generally, an agent uses 50 MB to 60 MB of RAM (all pageable). However, agents use additional memory when scanning (all pageable; the amount of memory depends on the scan configuration) and when updating plugins (all pageable). Agents use almost no CPU while idle, but they are designed to use up to 100% of CPU when available during jobs.

For more information on Tenable Agent resource usage, see Tenable Agent Performance.

The following table outlines the minimum recommended hardware for operating a Tenable Agent. You can install Tenable Agents 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

> 3 GB, not including space used by the host operating system

The agent may require more space during certain processes, such as applying a plugin update. The selected scan frequency, volume of findings, and log rotation options impact agent disk utilization. If disk space is a chief concern in your deployment scenario, Tenable recommends allocating up to 4 GB (not including space used by the host operating system).
Disk Speed 15-50 IOPS
Note: You can control the priority of the Tenable Agent relative to the priority of other tasks running on the system. For more information see Agent CPU Resource Control.

Tenable Nessus Manager

Scenario

Minimum Recommended Hardware

Tenable Nessus Manager with 0-10,000 agents

CPU — 4 2GHz cores

Memory — 16 GB RAM

Disk space — 5 GB per 5,000 agents per concurrent scan

Disk space —

  • Environments with triggered agent scanning — 5 MB x the number of agents x (the number of times those agents are triggered over seven days if initiating scans through Tenable Nessus Manager or the number of times those agents are triggered over two days if initiating scans through Tenable Security Center) + 500 MB

    For example:

    • If a standalone Tenable Nessus Manager is scanning daily with 1,100 agents, the disk space requirement is 5 MB x 1,100 x 7 + 500 MB = 39,000 MB (39 GB).

    • If Tenable Nessus Manager, managed by Tenable Security Center, is scanning daily with 1,100 agents, the disk space requirement is 5 MB x 1,100 x 2 + 500 MB = 11,500 MB (11.5 GB).

  • Environments without triggered agent scanning — 5 GB per 5,000 agents per concurrent scan

Note: Scan results and plugin updates require more disk space over time.

Tenable Nessus Manager with 10,001-20,000 agents

 

CPU — 8 2GHz cores

Memory — 32 GB RAM

Disk space — 5 GB per 5,000 agents per concurrent scan

Disk space —

  • Environments with triggered agent scanning — 5 MB x the number of agents x (the number of times those agents are triggered over seven days if initiating scans through Tenable Nessus Manager or the number of times those agents are triggered over two days if initiating scans through Tenable Security Center) + 500 MB

    For example:

    • If a standalone Tenable Nessus Manager is scanning daily with 15,000 agents, the disk space requirement is 5 MB x 15,000 x 7 + 500 MB = 525,500 MB (525.5 GB).

    • If Tenable Nessus Manager, managed by Tenable Security Center, is scanning daily with 15,000 agents, the disk space requirement is 5 MB x 15,000 x 2 + 500 MB = 150,500 MB (150.5 GB).

  • Environments without triggered agent scanning — 5 GB per 5,000 agents per concurrent scan

Notes:

  • Scan results and plugin updates require more disk space over time.

  • Engage with your Tenable representative for large deployments.