DISK HEALTH MONITORING

Know before
your disk fails

Your disks degrade for weeks before they fail. Prefail catches it — and alerts you in Telegram with what's wrong and what to do. SATA, NVMe, MegaRAID, Adaptec.

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Free for up to 2 servers · No credit card
Opens in Telegram · Sample data in 30 seconds
9:41PREFAIL100%
25+
S.M.A.R.T. attributes analyzed
<60s
Alert latency
~15 KB
Agent footprint
0
Dependencies
SPECIALIST vs GENERALIST

Your monitoring tells you when a disk is full.
Prefail tells you when a disk is dying.

Most infrastructure monitoring is broad and shallow — 500 metrics per host, threshold alerts, email digests. Prefail does one thing: S.M.A.R.T. health, deep.

Feature smartd + email Zabbix / PRTG Datadog Prefail
Scoring Threshold only Threshold only Threshold only 25+ attribute weighted score
Trend velocity No Manual setup No Auto: rising / stable / degrading
Hardware RAID behind controller No Limited No MegaRAID, Adaptec, mdadm
Time to deploy 30 min/server 2-4 hours 15 min + $15/host/mo 60 seconds
Weekly fleet digest No No Custom build Auto PDF every Monday
Cost at 50 servers Free (setup cost) Free (setup cost) $750/mo $39/mo

A specialist tool replaces one part of your monitoring stack. It does not compete with Datadog — it covers what Datadog does not.

SETUP

Three commands.
Five minutes.

01

Register

Open @prefail_bot in Telegram, tap Get Started, name your server. You get a unique token — paste it into the install command.

02

Install

A single shell script. No Python, no Docker, no daemon to manage.

wget -O diskwatch.sh https://prefail.io/diskwatch.sh
bash diskwatch.sh --token YOUR_TOKEN
# ~60 seconds. Systemd service. 250 lines of bash.
03

Monitor

Agent reports in 5 minutes. Alerts, weekly digests, and the full Mini App dashboard — all automatic.

TELEGRAM MINI APP

Full dashboard.
Inside Telegram.

Everything you need to manage disk health across your fleet — without leaving Telegram. Tap any server, see every disk, act on every alert.

Don't use Telegram? Email alerts available on all plans (Free: 1 recipient, Pro: 3, Business: 5, Scale/Enterprise: unlimited).

9:41PREFAIL100%
9:41PREFAIL100%
9:41PREFAIL100%
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Weekly PDF reports

Every Monday, a PDF lands in your Telegram: which disks degraded, what changed, what to replace this week. Forward it to your team or print it for the rack.

Download sample report
PREFAIL Weekly Report
4
Srv
22
OK
3
Wrn
1
Crt
sdgCRC 262K72
sdaRealloc: 332
sdbOK0
CAPABILITIES

Not just alerts.
A complete toolkit.

01

Health Scoring

Every disk gets a 0–100 risk score. Not just threshold checks — SENTINEL weighs 25+ SMART attributes by statistical failure correlation, detects velocity of change (a counter growing 10×/day matters more than its absolute value), and classifies trends as rising, stable, or new. The same score gets different urgency based on whether the situation is accelerating or static.

02

Trend Analysis

Score history charts with 7-day deltas. Stable or rising classification per signal. See degradation velocity before it becomes critical.

03

Real-time Alerts

Telegram push with email fallback. Each alert: severity, human-readable explainer, actionable recommendation. Ack, mute, or batch dismiss.

04

Expert Mode

Toggle raw S.M.A.R.T. counters inline with disk rows. Reallocated sectors, current pending, CRC errors — all the numbers, always available.

05

Hardware RAID

MegaRAID 9260/9361/9460, Adaptec SmartRAID, Linux mdadm. Individual disk health behind the controller, BBU status, array state.

06

Dark + AMOLED

Full dark theme with pure-black AMOLED variant. Auto-detects Telegram scheme, manual toggle. CloudStorage-persisted preferences.

Batch acknowledge
Custom mute 1h/4h/24h
Weekly digests
Score history 365d
Data export JSON
Per-disk notes
PDF health reports
TOTP two-factor auth
Global mute (vacation mode)
Tap alert → see the disk
TRANSPARENCY

You run it on
your servers. You should
know what it does.

Open agent

The agent is ~250 lines of bash. It runs smartctl, formats the output, and sends it via curl. Read every line before you install.

Minimal footprint

Collects only S.M.A.R.T. data. No file access, no network scanning, no process listing. Runs every 5 minutes, sleeps between.

Encrypted transport

TLS-encrypted channel with per-server API token bound to machine_id. Each server authenticates independently. No shared secrets between servers.

Your data, our server

Data stored on a dedicated server in Europe. No third-party analytics, no tracking pixels, no data resale. GDPR-ready data export and deletion.

What Prefail does not replace

S.M.A.R.T. detects gradual degradation — not sudden failures from power surges, controller burnout, or electrical damage. Prefail is an early warning system, not a substitute for backups. Always maintain tested, off-site backups of critical data.

PRICING

Simple plans.
No per-server math.

Every plan includes S.M.A.R.T. scoring, Telegram alerts, Mini App, and RAID support. Higher tiers unlock faster polling, longer history, and more email recipients.

Annual billing: ~17% off (2 months free). No credit card for Free.

FREE
$0
Up to 2 servers
forever
PULSE 30–60 min
7-day score history
Telegram alerts
Email alerts (1 recipient)
Get Started
PRO
$9/mo
Up to 20 servers
per account
PULSE 5–30 min
90-day score history
Telegram alerts
Email alerts (3 recipients)
Weekly PDF digest
Upgrade to Pro
BUSINESS
$39/mo
Up to 75 servers
per account
PULSE 5–30 min
180-day score history
Telegram alerts
Email alerts (5 recipients)
Weekly PDF digest
Upgrade to Business
SCALE
$149/mo
Up to 250 servers
per account
PULSE 1–30 min
365-day score history
Telegram alerts
Email alerts (unlimited)
Weekly PDF digest
Priority support
Upgrade to Scale
ENTERPRISE
Custom
Unlimited servers
for large fleets
PULSE 1 min
Unlimited score history
Telegram alerts
Email alerts (unlimited)
Weekly PDF digest
Priority support
SLA / SSO / audit log
Contact Us

Maintenance windows, REST API, webhooks, and team access are coming in Q2–Q3 2026 for Business tier and above.

The cost of one disk failure
vs. a year of monitoring

ONE UNPLANNED DISK FAILURE
Replacement hardware$150–500
Emergency labor (nights/weekends)$200–1,000
Downtime (1–8 hours)$500–10,000
Data recovery (if RAID rebuild fails)$1,000–15,000
Reputation / SLA penaltiesUnquantifiable
Typical total$2,000–25,000
vs
ONE YEAR OF PREFAIL
Up to 2 servers (Free)$0/year
Up to 20 servers (Pro)$108/year
Up to 75 servers (Business)$468/year
Up to 250 servers (Scale)$1,788/year
Pays for itselfwith 1 prevented incident

At 200 servers with 1,000+ disks, expect 20–50 failures per year. Each one is 2 AM, a panicked Slack thread, and a scramble for replacement hardware. Or: a Telegram notification three weeks in advance. Prefail catches the ~80% of failures that are preceded by S.M.A.R.T. degradation. For the rest — power surges, controller failures, physical damage — maintain tested backups.

Disks don't fail without warning.
They fail without someone listening.

Your first 2 servers are free, forever. Start monitoring in 5 minutes.

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