What it checks

Everything a technician needs to decide: keep, watch, back up, or replace.

💾

Native SMART, no smartctl

Reads ATA, SCSI/SAS and NVMe health straight from the kernel (HDIO, SG_IO, NVMe admin). Works in a minimal rescue system. If smartmontools is installed, both sources are merged.

🖥

Built for server RAID controllers

Tested on Dell PERC H330/H730 (LSI MegaRAID 3008/3108): SAS health status, grown defects, error counters, SAS link rate and phy errors, and full SMART for SATA SSDs behind the controller (ATA pass-through, no smartctl needed).

⏳

Remaining-life estimates

SSD: vendor / ACS wear indicator or host writes vs rated TBW. HDD: power-on hours vs design life and the drive's rated start-stop / load-unload cycles. Shown for 24/7 and 8h/day, with a confidence level.

🚨

Health gate & alerts

dcheck check exits 0/1/2/3 by the worst verdict — drop it into cron, systemd or CI. dcheck watch alerts on any change for the worse and can POST a webhook.

📊

Prometheus & JSON

dcheck prometheus prints health severity, temperature, power-on hours, bytes written and more for your scraper. Every report is also available as stable JSON.

🧠

RAM & CPU too

Memory usage, ECC errors (EDAC), DIMM slot map with vendor / type / speed from SMBIOS, DDR5 temperature. CPU model, topology, clock, cache, load, and per-socket temperatures judged against each CPU's own limits.

📟

A terminal UI that works anywhere

Neon truecolor in modern terminals, the ANSI palette on a Linux console or iDRAC/iLO virtual console, --plain for ASCII-only fonts, NO_COLOR respected, text stays selectable.

🔒

Read-only and safe

Never writes to a disk. Self-tests and the read benchmark only run when you ask. Ceph RBD, DRBD, device-mapper and loop devices are skipped automatically. A drive that is plugged in but never answers is still listed (from the kernel log) as REPLACE.

🔄

One binary, self-updating

~1 MB binary for Linux (static musl) and macOS, x86_64 and arm64. dcheck update downloads the latest release, verifies its SHA-256 checksum and replaces itself atomically.

Every screen

Captured on two Dell PowerEdge R630 servers (serial numbers masked). Click to enlarge; arrow keys to navigate.

Command deck with live storage, memory and processor cards

Command deck — live summary of every module

Storage array: SATA SSD and four SAS HDDs behind a PERC controller

Storage array — SSD + 4 SAS HDDs behind a PERC H730

Storage array with two drives flagged MONITOR

Alerts at a glance — two drives past their design life

Report of an HDD 5.5 years past its design life

HDD report — 5.5 years past its design life

SAS HDD report with manufacture date, cycles and design life

SAS HDD — manufacture date, rated cycles, design life

SATA SSD report with wear, lifetime temperatures and device statistics

SATA SSD — wear, lifetime temperatures, device statistics

Memory bank with usage, swap, DIMM slot map and ECC

Memory — usage, DIMM slot map, ECC

Processor dashboard with load, temperature and an 80-thread grid

Processor — load, temperature, 80-thread grid

Command reference overlay

Boot splash (0.5 s, any key skips)

Install

Any Linux distribution on x86_64 or aarch64 (static binary, nothing else required), and macOS on Apple Silicon or Intel.

1. One-line install

$ curl -fsSL https://wayang.dalang.io/dcheck/install.sh | sh

Detects the architecture, downloads the release, verifies SHA-256 and installs to /usr/local/bin (with sudo if needed, or ~/.local/bin). Options: DCHECK_INSTALL_DIR=/opt/bin, DCHECK_VERSION=0.2.8 (pin a version).

2. Run it

$ sudo dcheck # terminal UI (SMART needs root) $ sudo dcheck check # one line per disk, exit code = worst verdict $ sudo dcheck storage /dev/sdb # full report for one disk $ dcheck ram && dcheck cpu # memory / processor

Offline or air-gapped server? Download the tarball for your architecture from the release directory below, copy it over, and run tar xzf + install.

3. Keep it current

$ dcheck update --check # is there a newer release? $ sudo dcheck update # download, verify SHA-256, replace in place

Optional: smartmontools as a second source

# preview first: shows the package command, changes nothing $ curl -fsSL https://wayang.dalang.io/dcheck/install.sh | sh -s -- --with-smartmontools --dry-run # install dcheck + smartmontools $ curl -fsSL https://wayang.dalang.io/dcheck/install.sh | sh -s -- --with-smartmontools

Uses apt, dnf, yum, zypper, apk, pacman or brew; skipped if already installed. Add --dry-run to see what would happen. Not required: SATA, SAS and NVMe — including SATA behind PERC/MegaRAID and USB bridges — are read natively.

Requirements

What	Needed?	Why
Runtime libraries	none	Static binary (musl) — any distribution, rescue systems, containers
curl / wget, sha256sum, tar, awk	installer & update	Present on stock Ubuntu, Debian, Fedora, RHEL. Minimal container: apt install -y curl ca-certificates
root (sudo)	for SMART	Raw disk access; without it the disk list still works
smartmontools	optional	Second SMART source, merged with the native read
dmidecode	optional	RAM module detail; SMBIOS is also read directly from sysfs
curl	optional	Only for dcheck watch --webhook

Manual download

Platform	File
Linux x86_64 (Dell / HPE / Supermicro, most PCs)	dcheck-0.2.8-x86_64-unknown-linux-musl.tar.gz
Linux aarch64 (Ampere, Raspberry Pi 4/5, Orange Pi)	dcheck-0.2.8-aarch64-unknown-linux-musl.tar.gz
macOS Apple Silicon (M1–M4)	dcheck-0.2.8-aarch64-apple-darwin.tar.gz
macOS Intel	dcheck-0.2.8-x86_64-apple-darwin.tar.gz
Checksums	SHA256SUMS

Releases are immutable: a published version never changes. Older versions stay available under /dcheck/v<version>/.

For server technicians

From a one-off check during a site visit to continuous monitoring of a whole fleet.

Triage in five minutes

Install and run sudo dcheck check — one line per disk with its verdict and the reason.
Open sudo dcheck → Storage. The array table shows health, remaining life and temperature for every drive, even behind a PERC / MegaRAID controller.
Enter on a flagged drive: VITALS explains why (defects, pending sectors, wear, age, cycles) and the telemetry log has every counter. Press c to copy the report into a ticket.
Match the drive to a bay with the model and the last four serial digits, then plan the swap by verdict (table below).
Leave monitoring behind: a timer with dcheck check, a Prometheus scrape, or dcheck watch --webhook.

What the verdicts mean

Verdict	Means	Do	exit
✔ OK	No failure signs.	Nothing. Re-check periodically.	0
? UNKNOWN	No SMART data (not root, USB bridge, SD card).	Run with sudo; the report says why.	1
▲ MONITOR	Early warning: reallocated sectors, CRC errors, high temperature, past design life.	Watch the trend, check cables and cooling, order a spare.	2
✖ BACK UP NOW	Pending / uncorrectable sectors, media errors, attribute at threshold, wear ≥ 90%.	Back up immediately, schedule the swap.	3
✖ REPLACE	The drive reports SMART failure, or it is plugged in but never answers (dead drive, listed as ataN).	Replace now.	3

Real output — Dell R630, PERC H330

$ sudo dcheck check; echo "exit=$?" /dev/sda OK /dev/sdb MONITOR past its design life (power-on hours at 210% of rating) — plan a replacement /dev/sdc MONITOR past its design life (power-on hours at 176% of rating) — plan a replacement exit=2

$ sudo dcheck storage /dev/sdb … ▐ HEALTH Verdict : MONITOR SMART status : passed Temperature : 39°C Manufactured : 2014 week 48 — 11.8 years old In service : 91992 h powered on ≈ 10.5 y @24/7, on 89% of the time since manufacture Start-stop : 104 of 50000 rated Load-unload : 8664 of 200000 rated Written : 84.6 TB (host) Read : 4.3 PB Grown defects: 0 Uncorrected : 0 errors Design life : 43800 h (5.0 y @24/7, assumed — drives do not report it) Life used : 210% (limited by power-on hours) Life left : 0 — past its rated life by ~5.5y @24/7

Daily check with a systemd timer

# /etc/systemd/system/dcheck.service [Service] Type=oneshot ExecStart=/usr/local/bin/dcheck check # /etc/systemd/system/dcheck.timer [Timer] OnCalendar=daily Persistent=true [Install] WantedBy=timers.target

systemctl enable --now dcheck.timer. A non-zero exit marks the unit failed, so any existing alerting on failed units (or OnFailure=) picks it up.

Prometheus (node_exporter textfile)

# cron: every 15 minutes */15 * * * * root dcheck prometheus > /var/lib/node_exporter/dcheck.prom.tmp && mv /var/lib/node_exporter/dcheck.prom.tmp /var/lib/node_exporter/dcheck.prom # alert rule - alert: DiskHealthDegraded expr: dcheck_health_severity >= 2 for: 1h annotations: summary: "{{ $labels.device }} on {{ $labels.instance }} is {{ $labels.verdict }}"

# sample (Dell R630) dcheck_health_severity{device="/dev/sda",verdict="OK"} 0 dcheck_health_severity{device="/dev/sdb",verdict="MONITOR"} 2 dcheck_temperature_celsius{device="/dev/sdb"} 39 dcheck_power_on_hours{device="/dev/sdb"} 91992 dcheck_written_bytes{device="/dev/sdb"} 84573621806592

Webhook alerts (Slack, Discord, n8n, your API)

$ sudo dcheck watch --interval 3600 --webhook https://hooks.example.com/dcheck

Posts only when something gets worse (a new issue or a worse verdict):

{"event":"dcheck.alert", "alerts":["/dev/sdb worsened: OK -> MONITOR"], "devices":[{"device":"/dev/sdb","verdict":"MONITOR","severity":2, "issues":["past its design life (power-on hours at 210% of rating) — plan a replacement"], "notes":[]}]}

JSON for inventory and scripts

$ sudo dcheck storage /dev/sdb --json | jq .health { "verdict": "MONITOR", "temperature_c": 39, "power_on_hours": 91992, "manufactured": "2014-W48", "design_life_hours": 43800, "design_life_used_percent": 210, "remaining_hours": 0, "issues": ["past its design life (power-on hours at 210% of rating) — plan a replacement"], … }

↑ ↓ / j k	Move / scroll	Enter	Open
Esc / b	Back	1 2 3	Storage / memory / processor
PgUp PgDn g G	Page / top / bottom	r	Rescan / refresh
c	Copy the log (OSC 52)	? / q	Help / quit

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