What are Linux control groups (cgroups), and how does Docker leverage them for resource limits?

Q: What are Linux control groups (cgroups), and how does Docker leverage them for resource limits?

> **Control Groups (cgroups)** are a Linux kernel feature that enforces **resource limits** and metering on processes. Docker uses cgroups to guarantee that containers do not monopolize host resources. It controls limits for: * **CPU**: Allocate specific cores or limit CPU execution cycles (e.g., `--cpus=2`). * **Memory**: Set maximum RAM and swap thresholds (e.g., `-m 512m` to prevent out-of-memory issues on the host). * **I/O**: Limit block device write/read bandwidth.

💬Answer

Control Groups (cgroups) are a Linux kernel feature that enforces resource limits and metering on processes. Docker uses cgroups to guarantee that containers do not monopolize host resources. It controls limits for:

CPU: Allocate specific cores or limit CPU execution cycles (e.g., --cpus=2).
Memory: Set maximum RAM and swap thresholds (e.g., -m 512m to prevent out-of-memory issues on the host).
I/O: Limit block device write/read bandwidth.

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