fix(sat): serialize recurring IPMI polling behind one shared telemetry pipeline

The fan-ceiling check, the webui metrics collector (every 5s) and the PSU
health poller each shelled out to ipmitool independently. The BMC's KCS
interface serializes those calls anyway, so under load the concurrent
`ipmitool sdr`/`dcmi power reading` invocations just queued behind each
other — that's what produced "IPMI slow" backoff during a fan-ceiling run in
a blackbox dump, while the dashboard looked fine only because it was reading
its own, separately-stale data from a different ipmitool call.

hw_telemetry.go is now the sole recurring poller (fan RPM, temperature, PSU
power/status, DCMI system power), with the adaptive 1s-30s backoff that used
to be duplicated inside the fan check. Every hot-path consumer reads the
shared cache (hwSnapshot / platform.HardwareSDRSnapshot) instead of calling
ipmitool itself.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

audit/internal/platform/benchmark_power_calibration.go

@@ -197,11 +197,12 @@ func filterSensorGroup(sensors []sdrSensor, maxPerSensorW float64) (valid []sdrS
 // GPU slot sensors (GPU_POWER_SLOTx, GPU1 Power, …) are classified separately
 // since the audit collector does not track GPU PCIe slot power.
 func sampleIPMISDRPowerSensors() sdrPowerSnapshot {
-	raw, err := exec.Command("ipmitool", "sdr").Output()
-	if err != nil || len(raw) == 0 {
+	// Reads from the shared hardware telemetry cache (hwSnapshot) rather than
+	// shelling out to `ipmitool sdr` itself — see hw_telemetry.go for why.
+	sdrStr := hwSnapshot().Raw
+	if sdrStr == "" {
 		return sdrPowerSnapshot{}
 	}
-	sdrStr := string(raw)
 	var snap sdrPowerSnapshot
 
 	// ── PSU data via audit collector ─────────────────────────────────────────
@@ -390,20 +391,16 @@ func summarizeSDRPowerSeries(samples []sdrPowerSnapshot) benchmarkSDRSeriesSumma
 	return summary
 }
 
-// queryIPMIServerPowerW reads the current server power draw via ipmitool dcmi.
-// Returns 0 and an error if IPMI is unavailable or the output cannot be parsed.
+// queryIPMIServerPowerW reads the current server power draw from the shared
+// hardware telemetry cache (hwSnapshot), which runs `ipmitool dcmi power
+// reading` itself on its own cadence — see hw_telemetry.go for why this
+// doesn't shell out directly. Returns 0 and an error if IPMI dcmi power is
+// unavailable on this BMC.
 func queryIPMIServerPowerW() (float64, error) {
-	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-	defer cancel()
-	cmd := exec.CommandContext(ctx, "ipmitool", "dcmi", "power", "reading")
-	out, err := cmd.Output()
-	if err != nil {
-		return 0, fmt.Errorf("ipmitool dcmi power reading: %w", err)
-	}
-	if w := parseDCMIPowerReading(string(out)); w > 0 {
+	if w := hwSnapshot().DCMIPowerW; w > 0 {
 		return w, nil
 	}
-	return 0, fmt.Errorf("could not parse ipmitool dcmi power reading output")
+	return 0, fmt.Errorf("ipmitool dcmi power reading unavailable")
 }
 
 // characterizeServerPower computes BenchmarkServerPower from idle and loaded

audit/internal/platform/hw_telemetry.go

@@ -0,0 +1,188 @@
+package platform
+
+import (
+	"os/exec"
+	"sync"
+	"time"
+)
+
+// hwSample is one full snapshot from the shared hardware telemetry pipeline.
+type hwSample struct {
+	At time.Time
+	// Raw is the full `ipmitool sdr` text, for consumers that need to
+	// re-derive something the pre-parsed fields below don't cover.
+	Raw        string
+	Fans       []FanReading
+	Temps      []TempReading
+	PSUs       []PSUReading
+	FanStatus  map[string]string // fan name -> ipmi status word (ok/cr/nr/...)
+	DCMIPowerW float64
+	ReadDur    time.Duration
+}
+
+const (
+	hwPollFloor = 1 * time.Second
+	hwPollCeil  = 30 * time.Second
+	hwReadTMO   = 8 * time.Second
+)
+
+// hwTelemetry is the single owner of every recurring, hot-path IPMI poll for
+// fan RPM, temperature and PSU power/status (plus DCMI system power). Before
+// this existed, the webui metrics collector (every 5s), the PSU health
+// poller and the fan-ceiling check each shelled out to ipmitool on their own
+// schedule. The BMC's KCS interface serializes those calls anyway, so
+// running several concurrently only produced queueing — that's what shows up
+// as "ipmitool slow" backoff in blackbox dumps taken during a fan-ceiling
+// run, even while the dashboard looked fine (it was quietly reading its own,
+// separately-stale data from a different ipmitool invocation).
+//
+// Now exactly one `ipmitool sdr` (+ one `dcmi power reading`) round trip is
+// ever in flight, on a single adaptively-throttled background goroutine;
+// every consumer below reads the shared cache via hwSnapshot instead of
+// shelling out itself. One-off, non-recurring ipmitool calls (audit bundle
+// export, pre/post-test PSU fault diffing) are intentionally left alone —
+// they don't run on a sustained cadence, so they aren't the source of
+// contention this pipeline exists to remove.
+type hwTelemetry struct {
+	mu       sync.Mutex
+	sample   hwSample
+	interval time.Duration
+	degraded bool
+	started  bool
+}
+
+var hw = &hwTelemetry{interval: hwPollFloor}
+
+// hwSnapshot returns the most recent shared telemetry sample, starting the
+// background poller (and blocking for its first read) on first use.
+func hwSnapshot() hwSample {
+	hw.ensureStarted()
+	hw.mu.Lock()
+	defer hw.mu.Unlock()
+	return hw.sample
+}
+
+// hwCurrentInterval returns the poller's current adaptive polling interval —
+// above hwPollFloor means IPMI has been observed slow recently.
+func hwCurrentInterval() time.Duration {
+	hw.mu.Lock()
+	defer hw.mu.Unlock()
+	return hw.interval
+}
+
+// HardwareSDRSnapshot exposes the shared `ipmitool sdr` cache to other
+// packages (e.g. webui's PSU health poller) so they don't have to run their
+// own independent ipmitool poll — see hw_telemetry.go for why that matters.
+// Returns the raw SDR text and when it was captured; raw is empty if no
+// successful read has happened yet.
+func HardwareSDRSnapshot() (raw string, at time.Time) {
+	s := hwSnapshot()
+	return s.Raw, s.At
+}
+
+func (p *hwTelemetry) ensureStarted() {
+	p.mu.Lock()
+	if p.started {
+		p.mu.Unlock()
+		return
+	}
+	p.started = true
+	p.mu.Unlock()
+	p.pollOnce() // synchronous warm-up: the first caller gets a real reading, not an empty cache
+	go p.loop()
+}
+
+func (p *hwTelemetry) loop() {
+	for {
+		wait := p.pollOnce()
+		time.Sleep(wait)
+	}
+}
+
+// pollOnce runs exactly one sequential BMC round trip (sdr, then dcmi),
+// updates the cache and the observed-peak stores, adapts the polling
+// interval to how slow the read was, and returns the interval to sleep
+// before the next poll.
+func (p *hwTelemetry) pollOnce() time.Duration {
+	start := time.Now()
+	raw, ok := runIPMIBounded(hwReadTMO, "sdr")
+	readDur := time.Since(start)
+
+	var next time.Duration
+	p.mu.Lock()
+	next = p.interval
+	switch {
+	case !ok || readDur > hwReadTMO*3/4:
+		if next < hwPollCeil {
+			next = minDuration(next*2, hwPollCeil)
+		}
+		p.degraded = true
+	case next > hwPollFloor && readDur < hwPollFloor:
+		next = maxDuration(next*2/3, hwPollFloor)
+	}
+	p.interval = next
+	p.mu.Unlock()
+
+	if !ok {
+		return next
+	}
+
+	fans := parseFanSpeeds(raw)
+	temps := parseIPMITemps(raw)
+	psus := parsePSUReadings(raw)
+	fanStatus := parseFanStatuses(raw)
+
+	var dcmiW float64
+	if dcmiOut, dcmiOK := runIPMIBounded(hwReadTMO, "dcmi", "power", "reading"); dcmiOK {
+		dcmiW = parseDCMIPowerReading(dcmiOut)
+	}
+
+	now := time.Now()
+	p.mu.Lock()
+	p.sample = hwSample{
+		At:         now,
+		Raw:        raw,
+		Fans:       fans,
+		Temps:      temps,
+		PSUs:       psus,
+		FanStatus:  fanStatus,
+		DCMIPowerW: dcmiW,
+		ReadDur:    readDur,
+	}
+	p.mu.Unlock()
+
+	if len(fans) > 0 {
+		updateFanObservation(fans, now)
+	}
+	if len(psus) > 0 {
+		updatePSUObservation(psus, now)
+	}
+	return next
+}
+
+// runIPMIBounded runs an ipmitool subcommand but never blocks the caller
+// longer than timeout: the read happens in a goroutine that is abandoned if
+// it does not return in time (a KCS read wedged in uninterruptible I/O
+// cannot be killed, so we leave it and move on). ok=false means "no usable
+// output this round" — the caller must treat that as missing data.
+func runIPMIBounded(timeout time.Duration, args ...string) (string, bool) {
+	type result struct {
+		out string
+		ok  bool
+	}
+	ch := make(chan result, 1)
+	go func() {
+		out, err := exec.Command("ipmitool", args...).Output()
+		if err != nil || len(out) == 0 {
+			ch <- result{}
+			return
+		}
+		ch <- result{string(out), true}
+	}()
+	select {
+	case r := <-ch:
+		return r.out, r.ok
+	case <-time.After(timeout):
+		return "", false
+	}
+}

audit/internal/platform/live_metrics.go

@@ -246,14 +246,23 @@ func sampleLiveTempsViaSensorsJSON() []TempReading {
 	return temps
 }
 
+// sampleLiveTempsViaIPMI reads temperatures from the shared hardware
+// telemetry cache (hwSnapshot) instead of shelling out to ipmitool itself —
+// see hw_telemetry.go for why.
 func sampleLiveTempsViaIPMI() []TempReading {
-	out, err := exec.Command("ipmitool", "sdr", "type", "Temperature").Output()
-	if err != nil || len(out) == 0 {
+	return hwSnapshot().Temps
+}
+
+// parseIPMITemps parses temperature entries out of `ipmitool sdr` text
+// (the full dump or a "type Temperature"-filtered one — both use the same
+// per-line format).
+func parseIPMITemps(raw string) []TempReading {
+	if raw == "" {
 		return nil
 	}
 	var temps []TempReading
 	seen := map[string]struct{}{}
-	for _, line := range strings.Split(strings.TrimSpace(string(out)), "\n") {
+	for _, line := range strings.Split(strings.TrimSpace(raw), "\n") {
 		parts := strings.Split(line, "|")
 		if len(parts) < 3 {
 			continue
@@ -353,16 +362,23 @@ func compactAmbientTempName(chip, name string) string {
 	return chip + " / " + name
 }
 
-// samplePSUPower reads per-PSU input power via IPMI SDR.
+// samplePSUPower reads per-PSU power from the shared hardware telemetry
+// cache (hwSnapshot) instead of shelling out to ipmitool itself — see
+// hw_telemetry.go for why. The observed-capacity store is fed once, inside
+// the shared poller, rather than by every caller.
+func samplePSUPower() []PSUReading {
+	return hwSnapshot().PSUs
+}
+
+// parsePSUReadings parses per-PSU power out of `ipmitool sdr` text.
 // Uses collector.PSUSlotsFromSDR (name-based matching) which works across
 // vendors where PSU sensors may not carry entity ID "10.N".
-// Returns nil when IPMI is unavailable or no PSU Watt sensors exist.
-func samplePSUPower() []PSUReading {
-	out, err := exec.Command("ipmitool", "sdr").Output()
-	if err != nil || len(out) == 0 {
+// Returns nil when no PSU Watt sensors exist.
+func parsePSUReadings(raw string) []PSUReading {
+	if raw == "" {
 		return nil
 	}
-	slots := collector.PSUSlotsFromSDR(string(out))
+	slots := collector.PSUSlotsFromSDR(raw)
 	if len(slots) == 0 {
 		return nil
 	}
@@ -393,9 +409,5 @@ func samplePSUPower() []PSUReading {
 	if len(psus) == 0 {
 		return nil
 	}
-	// Feed the observed-capacity store (the "autotune" for PSU load scaling on
-	// BMCs that report only instantaneous power) — every load run that samples
-	// PSU power, including the 5 s metrics collector, refines it.
-	updatePSUObservation(psus, time.Now())
 	return psus
 }

audit/internal/platform/sat_fan_stress.go

@@ -196,20 +196,19 @@ func (s *System) RunFanCheck(ctx context.Context, baseDir string, opts FanCheckO
 	appendSATVerboseLog(verboseLog, fmt.Sprintf("%d load source(s) active; plateau clock effective from +%.0fs",
 		activeLoads, readyAt.Sub(start).Seconds()))
 
-	// ── Sample loop with IPMI-hang protection.
+	// ── Sample loop, reading the shared hardware telemetry cache.
 	//
-	// Under full load ipmitool over KCS can take tens of seconds per call or
-	// wedge outright. So: every fan read is time-boxed (readFansBounded runs
-	// it in a goroutine we abandon on timeout — a wedged KCS read can never
-	// block this loop), and the polling interval backs off geometrically when
-	// reads are slow and tightens again when they recover. A plateau is only
-	// declared while telemetry is healthy (interval near the floor); a
-	// degraded run just rides out to MaxLoadSec and records the peak it saw.
-	const (
-		fanPollFloor = 1 * time.Second
-		fanPollCeil  = 30 * time.Second
-		fanReadTMO   = 8 * time.Second
-	)
+	// Fan RPM, PSU power and IPMI-hang protection all live in the shared
+	// hwTelemetry poller (hw_telemetry.go) now: it is the only thing that
+	// ever shells out to ipmitool on a recurring cadence, backs its own
+	// polling interval off geometrically when reads are slow (or wedge
+	// outright) and tightens again when they recover. This loop just ticks
+	// at the cache's floor interval and picks up whatever the shared poller
+	// last saw — it never spawns an ipmitool call of its own, so it can't
+	// add to the exact contention that made ipmitool slow in the first
+	// place. A plateau is only declared while telemetry is healthy (shared
+	// poller interval near the floor); a degraded run just rides out to
+	// MaxLoadSec and records the peak it saw.
 	type fanState struct {
 		peak        float64
 		lastRiseSec float64
@@ -220,7 +219,8 @@ func (s *System) RunFanCheck(ctx context.Context, baseDir string, opts FanCheckO
 	aborted := false
 	degraded := false
 	goodSamples := 0
-	poll := fanPollFloor
+	lastSampleAt := time.Time{}
+	lastLoggedInterval := hwPollFloor
 
 	// PSU peak draw, sampled at a slow cadence off the same loop — the fan
 	// check already drives the box to full power, so it is also the right run
@@ -243,39 +243,34 @@ loop:
 			break loop
 		case <-loadCtx.Done():
 			break loop // MaxLoadSec reached
-		case <-time.After(poll):
+		case <-time.After(hwPollFloor):
 		}
 		elapsed := time.Since(start).Seconds()
 
-		readStart := time.Now()
-		fans, ok := readFansBounded(fanReadTMO)
-		readDur := time.Since(readStart)
-
-		// Adapt the interval to how ipmitool is behaving.
-		switch {
-		case !ok || readDur > fanReadTMO*3/4:
-			if poll < fanPollCeil {
-				poll = minDuration(poll*2, fanPollCeil)
+		curInterval := hwCurrentInterval()
+		if curInterval != lastLoggedInterval {
+			if curInterval > lastLoggedInterval {
 				degraded = true
-				appendSATVerboseLog(verboseLog, fmt.Sprintf("[%.0fs] ipmitool slow (%.1fs, ok=%v) — polling backed off to %s",
-					elapsed, readDur.Seconds(), ok, poll))
-				logFunc(fmt.Sprintf("IPMI slow — fan polling backed off to %s", poll))
+				appendSATVerboseLog(verboseLog, fmt.Sprintf("[%.0fs] ipmitool slow — shared polling backed off to %s",
+					elapsed, curInterval))
+				logFunc(fmt.Sprintf("IPMI slow — fan polling backed off to %s", curInterval))
 			}
-		case poll > fanPollFloor && readDur < fanPollFloor:
-			poll = maxDuration(poll*2/3, fanPollFloor)
+			lastLoggedInterval = curInterval
 		}
-		if !ok {
-			continue
+
+		sample := hwSnapshot()
+		if sample.At.IsZero() || !sample.At.After(lastSampleAt) {
+			continue // no fresh reading from the shared poller yet
 		}
+		lastSampleAt = sample.At
 		goodSamples++
+		fans := sample.Fans
 
 		if elapsed-lastPSUSec >= 15 {
 			lastPSUSec = elapsed
-			if ps, ok := readPSUPowerBounded(fanReadTMO); ok {
-				for i, p := range ps {
-					if p.PowerW > psuPeakW[i] {
-						psuPeakW[i] = p.PowerW
-					}
+			for i, p := range sample.PSUs {
+				if p.PowerW > psuPeakW[i] {
+					psuPeakW[i] = p.PowerW
 				}
 			}
 		}
@@ -302,7 +297,7 @@ loop:
 
 		// Only trust a plateau while telemetry is healthy and we have enough
 		// recent samples to have actually seen a flat window.
-		healthy := poll <= 2*fanPollFloor && goodSamples >= 5
+		healthy := curInterval <= 2*hwPollFloor && goodSamples >= 5
 		if healthy && rampConfirmed && elapsed >= float64(opts.MinLoadSec) &&
 			time.Since(readyAt) >= time.Duration(opts.PlateauHoldSec)*time.Second && len(fanBy) > 0 {
 			allFlat := true
@@ -415,56 +410,6 @@ func maxDuration(a, b time.Duration) time.Duration {
 	return b
 }
 
-// readFansBounded runs "ipmitool sdr type Fan" but never blocks the caller
-// longer than timeout: the read happens in a goroutine that is abandoned if it
-// does not return in time (a KCS read wedged in uninterruptible I/O cannot be
-// killed, so we leave it and move on). ok=false means "no usable sample this
-// tick" — the caller must treat that as missing data, not as a flat fan.
-func readFansBounded(timeout time.Duration) ([]FanReading, bool) {
-	type result struct {
-		fans []FanReading
-		ok   bool
-	}
-	ch := make(chan result, 1)
-	go func() {
-		out, err := exec.Command("ipmitool", "sdr", "type", "Fan").Output()
-		if err != nil {
-			ch <- result{}
-			return
-		}
-		fans := parseFanSpeeds(string(out))
-		if len(fans) == 0 {
-			ch <- result{}
-			return
-		}
-		ch <- result{fans, true}
-	}()
-	select {
-	case r := <-ch:
-		if r.ok {
-			updateFanObservation(r.fans, time.Now())
-		}
-		return r.fans, r.ok
-	case <-time.After(timeout):
-		return nil, false
-	}
-}
-
-// readPSUPowerBounded is readFansBounded's PSU sibling: a time-boxed,
-// abandonable "ipmitool sdr" read of per-PSU power (samplePSUPower also feeds
-// the observed-capacity store). Used at a slow cadence during the fan check so
-// the same max-load run that finds fan ceilings also records peak PSU draw.
-func readPSUPowerBounded(timeout time.Duration) ([]PSUReading, bool) {
-	ch := make(chan []PSUReading, 1)
-	go func() { ch <- samplePSUPower() }()
-	select {
-	case ps := <-ch:
-		return ps, len(ps) > 0
-	case <-time.After(timeout):
-		return nil, false
-	}
-}
-
 // boundedGPUMaxTemp returns the hottest GPU temperature via a single
 // time-boxed nvidia-smi call, or 0 if unavailable.
 func boundedGPUMaxTemp(gpuIndices []int) float64 {
@@ -570,14 +515,23 @@ func sanitizeSummaryKey(name string) string {
 }
 
 // readFanStatuses returns the per-fan IPMI status word ("ok", "cr", "nr", ...)
-// from "ipmitool sdr type Fan". Empty map when ipmitool is unavailable.
+// from the shared hardware telemetry cache (hwSnapshot) instead of shelling
+// out to ipmitool itself — see hw_telemetry.go for why.
 func readFanStatuses() map[string]string {
-	out, err := exec.Command("ipmitool", "sdr", "type", "Fan").Output()
-	if err != nil {
+	return hwSnapshot().FanStatus
+}
+
+// parseFanStatuses parses the per-fan IPMI status word out of `ipmitool sdr`
+// text (the full dump or a "type Fan"-filtered one — both use the same
+// per-line format). Non-fan lines end up in the map too (keyed by whatever
+// sensor name they have) but that's harmless: callers only look up known fan
+// names.
+func parseFanStatuses(raw string) map[string]string {
+	if raw == "" {
 		return nil
 	}
 	m := map[string]string{}
-	for _, line := range strings.Split(string(out), "\n") {
+	for _, line := range strings.Split(raw, "\n") {
 		parts := strings.Split(line, "|")
 		if len(parts) < 3 {
 			continue
@@ -625,23 +579,19 @@ func ResolveFanMaxRPM(current map[string]float64) map[string]float64 {
 	return out
 }
 
-// sampleFanSpeeds reads fan RPM values from ipmitool sdr.
+// sampleFanSpeeds reads fan RPM values from the shared hardware telemetry
+// cache (hwSnapshot) instead of shelling out to ipmitool itself — see
+// hw_telemetry.go for why. Falls back to lm-sensors when IPMI has nothing
+// (unavailable BMC, or a platform without IPMI fan sensors at all).
 func sampleFanSpeeds() ([]FanReading, error) {
-	out, err := exec.Command("ipmitool", "sdr", "type", "Fan").Output()
-	if err == nil {
-		if fans := parseFanSpeeds(string(out)); len(fans) > 0 {
-			updateFanObservation(fans, time.Now())
-			return fans, nil
-		}
+	if fans := hwSnapshot().Fans; len(fans) > 0 {
+		return fans, nil
 	}
 	fans, sensorsErr := sampleFanSpeedsViaSensorsJSON()
 	if len(fans) > 0 {
 		updateFanObservation(fans, time.Now())
 		return fans, nil
 	}
-	if err != nil {
-		return nil, err
-	}
 	return nil, sensorsErr
 }
 
@@ -900,13 +850,16 @@ func firstFanInputValue(feature map[string]any) (float64, bool) {
 	return firstSensorInputValue(feature, "fan")
 }
 
-// sampleCPUMaxTemp returns the highest CPU/inlet temperature from ipmitool or sensors.
+// sampleCPUMaxTemp returns the highest CPU/inlet temperature, from the
+// shared hardware telemetry cache (hwSnapshot) when IPMI has it, else
+// lm-sensors directly.
 func sampleCPUMaxTemp() float64 {
-	out, err := exec.Command("ipmitool", "sdr", "type", "Temperature").Output()
-	if err != nil {
-		return sampleCPUTempViaSensors()
+	if raw := hwSnapshot().Raw; raw != "" {
+		if t := parseIPMIMaxTemp(raw); t > 0 {
+			return t
+		}
 	}
-	return parseIPMIMaxTemp(string(out))
+	return sampleCPUTempViaSensors()
 }
 
 // parseIPMIMaxTemp extracts the maximum temperature from "ipmitool sdr type Temperature".

audit/internal/webui/health_poller.go

@@ -1,14 +1,12 @@
 package webui
 
 import (
-	"bytes"
-	"context"
 	"log/slog"
-	"os/exec"
 	"time"
 
 	"bee/audit/internal/app"
 	"bee/audit/internal/collector"
+	"bee/audit/internal/platform"
 )
 
 const (
@@ -18,7 +16,6 @@ const (
 	// is still caught within a bounded window even after a long quiet
 	// stretch.
 	healthPollIntervalMax = 30 * time.Minute
-	psuIPMITimeout        = 15 * time.Second
 )
 
 // healthPoller runs periodic health checks for hardware components that do not
@@ -66,26 +63,26 @@ func nextHealthPollInterval(current time.Duration, changed bool) time.Duration {
 	return next
 }
 
-// pollPSU polls PSU status via ipmitool and records it to statusDB. Returns
-// true if any PSU's status differs from what statusDB currently has for it,
-// which run uses to reset the backoff.
+// pollPSU reads PSU status from the shared hardware telemetry cache
+// (platform.HardwareSDRSnapshot) and records it to statusDB, instead of
+// shelling out to ipmitool itself — see platform/hw_telemetry.go for why:
+// this poller used to run its own independent `ipmitool sdr` on a 60s+
+// cadence, competing with the webui metrics collector and any running SAT
+// test for the same serialized BMC interface. Returns true if any PSU's
+// status differs from what statusDB currently has for it, which run uses to
+// reset the backoff.
 func (p *healthPoller) pollPSU() bool {
 	if p.statusDB == nil {
 		return false
 	}
-	ctx, cancel := context.WithTimeout(context.Background(), psuIPMITimeout)
-	defer cancel()
-
-	cmd := exec.CommandContext(ctx, "ipmitool", "sdr")
-	var out bytes.Buffer
-	cmd.Stdout = &out
-	if err := cmd.Run(); err != nil {
-		// IPMI not available or not a server — skip silently.
-		slog.Debug("health poller: ipmitool sdr unavailable", "err", err)
+	raw, at := platform.HardwareSDRSnapshot()
+	if raw == "" || at.IsZero() {
+		// IPMI not available, or the shared poller hasn't completed a read yet.
+		slog.Debug("health poller: no shared ipmitool sdr sample available")
 		return false
 	}
 
-	slots := collector.PSUSlotsFromSDR(out.String())
+	slots := collector.PSUSlotsFromSDR(raw)
 	if len(slots) == 0 {
 		return false
 	}