Lion Cipher Lab
Triage a fleet's SMART disk data and measure what a flag predicts
- Cyber / Security Engineer
- Intermediate
- ~35 min
- Free · no account required
Why it matters
Disks fail, and when one fails without warning on a server whose backups are stale, data is lost. Most drives report health counters called SMART attributes, which you can read with the free smartmontools package. Backblaze, which runs hundreds of thousands of drives, published in 2016 which five attributes it watches (reallocated sectors, reported uncorrectable errors, command timeouts, pending sectors and uncorrectable sectors) and how often they appeared on drives that failed compared with drives that kept working. Those two numbers are the honest basis for a monitoring policy: a non-zero…
What you'll learn
- which SMART attributes are linked to drive failure
- triaging a fleet by non-zero and growing raw values
- using a 30-day trend to separate stable from worsening drives
- turning Backblaze's rates into a prediction with the base rate
- why most flagged drives may not fail, and some failures are never flagged
- what SMART monitoring can and cannot replace
Steps in this lab
- Five attributes and two numbers
- The fleet's SMART snapshot
- Write the triage
- Run it: two to replace, three to watch, and a base-rate surprise
- Set the policy, and keep the backups