CERN Disk Benchmark Tool

Prerequisites

• sysstat (for iostat) — e.g., sudo dnf install sysstat on RHEL/Alma
• python3 and pip
• python3 -m pip install matplotlib

One-shot full benchmark + report

./run-report.sh <mount-path> [parallelism=1] [stop-percent=99]

Runs write, then update, produces plots, and writes a PDF report.

• Plots:
  • /var/tmp/write-speed-<device>.jpg
  • /var/tmp/update-speed-<device>.jpg
• Report:
  • /var/tmp/benchmark-report-<device>-<hostname>-<unix_ts>.pdf
  • Contains host, run time, uname, lsblk, xfs_info, queue settings, hdparm cache, lspci SAS/SATA info, and embeds the plots.

If you want each step separately

Write benchmark

./run-write-benchmark.sh <mount-path> [parallelism=1] [stop-percent=99]

• Writes 800–1000 MiB chunks until the stop threshold.
• Seed file: /var/tmp/1GB.
• Log: /var/tmp/write-benchmark-<device>.log (usage%, MB/s).

Update benchmark (rewrite existing files)

./run-update-benchmark.sh <mount-path> [parallelism=1]

• Rewrites each file.* (non-recursive) once with the same size.
• Log: /var/tmp/update-benchmark-<device>.log (iostat).

Plots only

./plot_benchmark.py /var/tmp/write-benchmark-<device>.log out.jpg

• Generates a JPG plot of usage vs write speed.

Full benchmark only (write + update, no PDF)

./run-full-benchmark.sh <mount-path> [parallelism=1] [stop-percent=99]

• Runs write then update; saves the two plots above.

Low-level scripts (usually not called directly)

• scripts/write-benchmark.sh, scripts/write-benchmark
• scripts/update-benchmark.sh, scripts/update-benchmark