[Workload]: chaos-disk workload (disk fill pressure)

[mrhillsman]

Workload Name

chaos-disk

Workload Description

This workload uses fallocate and dd to fill a target mount point to a configurable percentage (default 90%), simulating disk pressure scenarios. It runs in a loop with fill/release cycles to create sustained disk pressure patterns.

Tooling and Packages

• Tool: fallocate, dd (available by default in base image)
• RPM packages: coreutils (pre-installed via golden image, see [Feature]: Golden container disk image with pre-installed workload tools #16)
• systemd service command: custom script with fallocate fill/release loop

VM Count Model

Single VM (like cpu, memory, disk)

Required Resources

• Persistent storage (DataVolume)
• Kubernetes Service (for inter-VM communication)
• Kubernetes Secret (for credentials or config)
• Additional CPU/memory beyond defaults
• GPU or special device passthrough

Cloud-Init Details

Packages: pre-installed via golden image (#16)
Systemd unit: disk fill loop targeting a configurable mount point with Restart=always
Write files: /usr/local/bin/chaos-disk.sh (fill/release cycle script)

Use Case

Disk pressure testing for validating that applications and monitoring systems handle disk saturation gracefully. Useful for testing Prometheus alerting rules for disk usage, validating eviction policies, and verifying application behavior under storage pressure.

Additional Context

Depends on golden container disk image (#16). Requires a DataVolume for persistent storage to fill.

Related Issues: #16 (golden image dependency), #17 (chaos-network sibling), #18 (chaos-process sibling)

Split from #15