Varaverk/Monitors/zfs_memory_snapshot.sh

#!/bin/bash
# ==============================================================================================
# ================================= ZFS Memory Snapshot ========================================
# ==============================================================================================
# Weekly ZFS pool health and memory diagnostic report.
# Combines ZFS pool status, ARC statistics, memory summary, Docker memory usage
# and kernel pressure into a single report. Informational only — no action taken.
# system_watchdog.sh handles threshold-based intervention.
#
# ── WHAT IT REPORTS ───────────────────────────────────────────────────────────────────────────
#   ZFS pool health   — status, state, errors per pool (excluding ignored pools)
#   ARC statistics    — current size, max, utilization %, metadata pressure
#   Memory status     — total/free/available RAM vs thresholds
#   Docker memory     — top ZFS_REPORT_DOCKER_TOP containers by memory usage
#   Kernel pressure   — vmstat snapshot (3 samples)
#
# ── OUTPUT ────────────────────────────────────────────────────────────────────────────────────
# Output goes to both console and ZFS_REPORT_LOG for later review.
# In dry-run mode — console only, nothing written to log.
# Notifies if any warning thresholds are exceeded.
# Silent when all healthy — only problems produce output.
#
# ── HOST AWARENESS ────────────────────────────────────────────────────────────────────────────
# detect_hosts() sets MY_ID and aliases HOST*_ZFS_REPORT_IGNORE_POOLS → ZFS_REPORT_IGNORE_POOLS.
# Each server ignores its own single-disk ZFS array pools — not the peer's.
#
# ── SAFEGUARDS ────────────────────────────────────────────────────────────────────────────────
#   acquire_lock         — zpool + docker stats are slow, prevent duplicates
#   detect_hosts()       — correct pool ignore list per host
#   validate_unraid_cmd  — notify validated before use
#   DOCKER_TIMEOUT       — docker stats protected against hung daemon
#   ZFS not available    — skips pool and ARC sections gracefully
#   Docker not available — skips container section gracefully
#
# ── CONFIGURATION (master_host*.conf) ─────────────────────────────────────────────────────────
#   HOST*_ZFS_REPORT_IGNORE_POOLS — pools excluded from health reporting
#   Aliased by detect_hosts() — script uses ZFS_REPORT_IGNORE_POOLS
#
# ── CONFIGURATION (master.conf) ───────────────────────────────────────────────────────────────
#   ZFS_REPORT_LOG           — log file path for weekly reports
#   ZFS_REPORT_ARC_WARN_PCT  — warn if ARC using more than this % of max
#   ZFS_REPORT_FREE_WARN_GB  — warn if less than this GB free RAM
#   ZFS_REPORT_AVAIL_WARN_GB — warn if less than this GB available RAM
#   ZFS_REPORT_DOCKER_TOP    — how many top Docker containers to show
#
# ── USAGE ─────────────────────────────────────────────────────────────────────────────────────
#   zfs_memory_snapshot.sh              — normal report (writes to log)
#   zfs_memory_snapshot.sh --dry-run    — console only, no log write
#   zfs_memory_snapshot.sh --log        — verbose output
#   zfs_memory_snapshot.sh --status     — show config and exit
# ==============================================================================================

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

source "$SCRIPT_DIR/../load_config.sh"

# Monitor/report script — output is the point
SILENT_MODE=false

parse_args "$@"

DOCKER_TIMEOUT=15

# ==============================================================================================
# ━━━ Setup ━━━
# ==============================================================================================
if [[ "$EUID" -ne 0 ]]; then
    error "Must be run as root"
    exit 1
fi

validate_unraid_cmd \
    "/usr/local/emhttp/plugins/dynamix/scripts/notify" \
    "" "" \
    "unRAID notify script" || warn "unRAID notify script not found — native notifications disabled"

acquire_lock

# detect_hosts() sets MY_ID and aliases HOST*_ZFS_REPORT_IGNORE_POOLS
detect_hosts

# Build ignore pool lookup map — O(1) check per pool
declare -A IGNORE_POOL_MAP
for pool in "${ZFS_REPORT_IGNORE_POOLS[@]}"; do
    [[ -n "$pool" ]] && IGNORE_POOL_MAP["$pool"]=1
done

log "Identity: $MY_ID ($LOCAL_SERVER_NAME)"
log "Ignoring pools: ${ZFS_REPORT_IGNORE_POOLS[*]:-none}"

# Tee output to log file unless dry run
if [[ "$DRY_RUN" == false ]]; then
    mkdir -p "$(dirname "$ZFS_REPORT_LOG")"
    exec > >(tee -a "$ZFS_REPORT_LOG") 2>&1
fi

[[ "$DRY_RUN" == true ]] && warn "DRY RUN — output will not be written to log"

# ==============================================================================================
# ━━━ Status ━━━
# ==============================================================================================
if [[ "$SHOW_STATUS" == true ]]; then
    echo ""
    echo "━━━━━ $ICON_SUMMARY STATUS ━━━━━"
    echo "$ICON_HOST       Identity:       $MY_ID ($LOCAL_SERVER_NAME)"
    echo "$ICON_ZFS        Log file:       $ZFS_REPORT_LOG"
    echo "$ICON_ZFS        ARC warn:       ${ZFS_REPORT_ARC_WARN_PCT}%"
    echo "$ICON_MEM        Free RAM warn:  ${ZFS_REPORT_FREE_WARN_GB}GB"
    echo "$ICON_MEM        Avail warn:     ${ZFS_REPORT_AVAIL_WARN_GB}GB"
    echo "$ICON_CONTAINERS Docker top:     $ZFS_REPORT_DOCKER_TOP"
    echo "$ICON_ZFS        Ignore pools:   ${ZFS_REPORT_IGNORE_POOLS[*]:-none}"
    echo "$ICON_GEAR       Dry Run:        $DRY_RUN"
    echo "━━━━━━━━━━━━━━━━━━━━━━━"
    exit 0
fi

# ==============================================================================================
# ━━━ Report ━━━
# ==============================================================================================
WARNINGS=()
START=$(date +%s)
DATE=$(date '+%Y-%m-%d %H:%M:%S')

echo ""
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "  $ICON_ZFS  ZFS WEEKLY HEALTH REPORT — $DATE"
echo "  $ICON_HOST $MY_ID — $LOCAL_SERVER_NAME"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"

# ── ZFS Pool Health ───────────────────────────────────────────────────────────────────────────
echo ""
echo "━━━ $ICON_ZFS ZFS Pool Health ━━━"

if ! command -v zpool >/dev/null 2>&1; then
    warn "ZFS not available on this system — skipping pool checks"
else
    # Pool status — filtered to key lines, ignoring specified pools
    CURRENT_POOL=""
    while IFS= read -r line; do
        if [[ "$line" =~ ^[[:space:]]*pool:[[:space:]]*(.+) ]]; then
            CURRENT_POOL="${BASH_REMATCH[1]// /}"
        fi
        [[ -n "${IGNORE_POOL_MAP[$CURRENT_POOL]:-}" ]] && continue
        echo "  $line"
    done < <(zpool status 2>/dev/null | grep -E "pool:|state:|status:|errors:|scan:")

    echo ""

    # Pool list — filter out ignored pools
    zpool list 2>/dev/null | while IFS= read -r line; do
        if [[ "$line" == NAME* ]]; then
            echo "  $line"
            continue
        fi
        pool_name=$(echo "$line" | awk '{print $1}')
        [[ -n "${IGNORE_POOL_MAP[$pool_name]:-}" ]] && continue
        echo "  $line"
    done

    # Check for unhealthy non-ignored pools
    UNHEALTHY=$(zpool list -H -o name,health 2>/dev/null | \
        while IFS=$'\t' read -r name health; do
            [[ -n "${IGNORE_POOL_MAP[$name]:-}" ]] && continue
            [[ "$health" != "ONLINE" ]] && echo "$name: $health"
        done)

    if [[ -n "$UNHEALTHY" ]]; then
        error "One or more ZFS pools are NOT ONLINE: $UNHEALTHY"
        WARNINGS+=("ZFS pool unhealthy: $UNHEALTHY")
    else
        log "All monitored ZFS pools are ONLINE ✅"
    fi

    if [[ ${#ZFS_REPORT_IGNORE_POOLS[@]} -gt 0 ]]; then
        log "Ignored pools: ${ZFS_REPORT_IGNORE_POOLS[*]}"
    fi
fi

# ── ARC Statistics ────────────────────────────────────────────────────────────────────────────
echo ""
echo "━━━ $ICON_ZFS ARC Statistics ━━━"

if [[ ! -f /proc/spl/kstat/zfs/arcstats ]]; then
    warn "ZFS arcstats not available — skipping ARC section"
else
    ARC_MAX=$(cat /sys/module/zfs/parameters/zfs_arc_max 2>/dev/null || \
              awk '/^c_max / {print $3}' /proc/spl/kstat/zfs/arcstats)
    ARC_SIZE=$(awk '/^size / {print $3}' /proc/spl/kstat/zfs/arcstats)
    ARC_META_USED=$(awk '/^arc_meta_used / {print $3}' /proc/spl/kstat/zfs/arcstats)

    ARC_MAX_GB=$(awk "BEGIN {printf \"%.1f\", $ARC_MAX / 1073741824}")
    ARC_CUR_GB=$(awk "BEGIN {printf \"%.1f\", $ARC_SIZE / 1073741824}")
    ARC_META_GB=$(awk "BEGIN {printf \"%.1f\", $ARC_META_USED / 1073741824}")
    ARC_PCT=$(awk "BEGIN {printf \"%.1f\", $ARC_SIZE * 100 / $ARC_MAX}")
    ARC_PCT_INT=$(printf "%.0f" "$ARC_PCT")

    echo "  $ICON_ZFS ARC Max:         ${ARC_MAX_GB}GB"
    echo "  $ICON_ZFS ARC Current:     ${ARC_CUR_GB}GB"
    echo "  $ICON_ZFS ARC Meta Used:   ${ARC_META_GB}GB"
    echo "  $ICON_ZFS ARC Utilization: ${ARC_PCT}%"

    if [[ "$ARC_PCT_INT" -ge "$ZFS_REPORT_ARC_WARN_PCT" ]]; then
        warn "ARC utilization ${ARC_PCT}% — above ${ZFS_REPORT_ARC_WARN_PCT}% threshold"
        WARNINGS+=("ARC high: ${ARC_PCT}%")
    else
        log "ARC utilization ${ARC_PCT}% — within threshold ✅"
    fi

    echo ""
    META_MRU_GHOST=$(awk '/^mru_ghost_metadata / {print $3}' \
        /proc/spl/kstat/zfs/arcstats 2>/dev/null || echo 0)
    META_MFU_GHOST=$(awk '/^mfu_ghost_metadata / {print $3}' \
        /proc/spl/kstat/zfs/arcstats 2>/dev/null || echo 0)
    META_MISSES=$(awk '/^demand_metadata_misses / {print $3}' \
        /proc/spl/kstat/zfs/arcstats 2>/dev/null || echo 0)

    MRU_GB=$(awk "BEGIN {printf \"%.2f\", $META_MRU_GHOST / 1073741824}")
    MFU_GB=$(awk "BEGIN {printf \"%.2f\", $META_MFU_GHOST / 1073741824}")

    echo "  $ICON_ZFS MRU Ghost:       ${MRU_GB}GB"
    echo "  $ICON_ZFS MFU Ghost:       ${MFU_GB}GB"
    echo "  $ICON_ZFS Metadata Misses: ${META_MISSES}"
fi

# ── Memory Status ─────────────────────────────────────────────────────────────────────────────
echo ""
echo "━━━ $ICON_MEM Memory Status ━━━"

FREE_HUMAN=$(free -h  | awk '/Mem:/ {print $4}')
AVAIL_HUMAN=$(free -h | awk '/Mem:/ {print $7}')
TOTAL_HUMAN=$(free -h | awk '/Mem:/ {print $2}')
FREE_GB=$(free -g     | awk '/Mem:/ {print $4}')
AVAIL_GB=$(free -g    | awk '/Mem:/ {print $7}')

echo "  $ICON_MEM Total RAM:      $TOTAL_HUMAN"
echo "  $ICON_MEM Free RAM:       $FREE_HUMAN"
echo "  $ICON_MEM Available RAM:  $AVAIL_HUMAN"

if [[ "$FREE_GB" -lt "$ZFS_REPORT_FREE_WARN_GB" ]]; then
    warn "Free RAM ${FREE_HUMAN} — below ${ZFS_REPORT_FREE_WARN_GB}GB threshold"
    WARNINGS+=("Low free RAM: ${FREE_HUMAN}")
else
    log "Free RAM ${FREE_HUMAN} — within threshold ✅"
fi

if [[ "$AVAIL_GB" -lt "$ZFS_REPORT_AVAIL_WARN_GB" ]]; then
    warn "Available RAM ${AVAIL_HUMAN} — below ${ZFS_REPORT_AVAIL_WARN_GB}GB threshold"
    WARNINGS+=("Low available RAM: ${AVAIL_HUMAN}")
else
    log "Available RAM ${AVAIL_HUMAN} — within threshold ✅"
fi

# ── Docker Memory ─────────────────────────────────────────────────────────────────────────────
echo ""
echo "━━━ $ICON_CONTAINERS Top $ZFS_REPORT_DOCKER_TOP Docker Memory Users ━━━"

if ! command -v docker >/dev/null 2>&1; then
    warn "Docker not available — skipping container memory section"
else
    timeout "$DOCKER_TIMEOUT" docker stats --no-stream \
        --format "table {{.Name}}\t{{.MemUsage}}\t{{.MemPerc}}" \
        2>/dev/null | head -n $(( ZFS_REPORT_DOCKER_TOP + 1 )) | \
        while IFS= read -r line; do
            echo "  $line"
        done
fi

# ── Kernel Pressure ───────────────────────────────────────────────────────────────────────────
echo ""
echo "━━━ $ICON_GEAR Kernel Pressure ━━━"

if ! command -v vmstat >/dev/null 2>&1; then
    warn "vmstat not available — skipping kernel pressure section"
else
    vmstat 1 3 2>/dev/null | while IFS= read -r line; do
        echo "  $line"
    done
fi

END=$(date +%s)

# ── Summary ───────────────────────────────────────────────────────────────────────────────────
echo ""
echo "━━━━━ $ICON_SUMMARY ZFS REPORT SUMMARY ━━━━━"
echo "$ICON_HOST    Identity: $MY_ID ($LOCAL_SERVER_NAME)"
echo "$ICON_TIME    Duration: $(format_duration $(( END - START )))"
echo "$ICON_ZFS     Log:      $ZFS_REPORT_LOG"
[[ ${#ZFS_REPORT_IGNORE_POOLS[@]} -gt 0 ]] && \
    log "Ignored: ${ZFS_REPORT_IGNORE_POOLS[*]}"
echo ""

if [[ ${#WARNINGS[@]} -eq 0 ]]; then
    log "$ICON_DONE All checks within thresholds ✅"
else
    echo "$ICON_WARN Warnings: ${#WARNINGS[@]}"
    for w in "${WARNINGS[@]}"; do
        echo "  $ICON_WARN $w"
    done
    notify "ZFS weekly report on $(hostname) — ${#WARNINGS[@]} warning(s): ${WARNINGS[*]}" \
        "ZFS Report" "warning"
fi
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"

[[ ${#WARNINGS[@]} -gt 0 ]] && exit 1
exit 0