NAS / BOTTLENECK
NAS transfer bottleneck diagnostic
Find the slowest transfer stage across source reads, network transport and destination writes.
Local only: Inputs are neither transmitted nor auto-saved. Keep paths, accounts and passwords out of JSON; this tool stores numeric assumptions only.
Bottleneck diagnostic model
- Changed data = source size × changed percentage
- Transferred data = changed data × (1 − compression savings)
- Effective network rate = link Mbps ÷ 8 × (1 − overhead)
- Total time is the longest of source read, network transfer and destination write stages.
The model assumes pipelined stages. File count, CPU compression rate, latency, retries, snapshot setup and wireless variation are excluded; calibrate with a real transfer.
Next: backup and restore planning
After finding the slow stage here, continue with 3-2-1 copies, retention policy and restore-time planning in Home Storage Lab.
2. Estimate
Logical source size—
Changed data to read—
Network transfer volume—
Estimated completion time—
Expected bottleneck—
Effective network rate—
Time by stage
| Source read | Network | Destination write |
|---|---|---|
| — | — | — |
How to use this: Improve the longest stage first. A 1GbE link is 125 MB/s before overhead and 112.5 MB/s at 10% overhead. A faster link will not help when source, destination or CPU is slower.