Skip to content

⚡ Bolt: Optimize swap-ssd-health.sh parsing and fix calculation bugs #4

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
simien merged 1 commit into from
Jan 3, 2026
Merged

⚡ Bolt: Optimize swap-ssd-health.sh parsing and fix calculation bugs #4

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
46 changes: 32 additions & 14 deletions ops/monitoring/swap-ssd-health.sh
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -54,9 +54,14 @@ if command -v sysctl &> /dev/null; then
SWAP_INFO=$(sysctl vm.swapusage 2>/dev/null)
log "$SWAP_INFO"

# Extract swap usage values
TOTAL_SWAP=$(echo "$SWAP_INFO" | grep 'total' | awk '{print $4}' | sed 's/M//' | sed 's/\..*//')
USED_SWAP=$(echo "$SWAP_INFO" | grep 'used' | awk '{print $4}' | sed 's/M//' | sed 's/\..*//')
# Extract swap usage values efficiently using awk
# vm.swapusage: total = 1024.00M used = 512.50M ...
# awk gets fields $4 (total) and $7 (used)
read -r TOTAL_SWAP USED_SWAP <<< $(echo "$SWAP_INFO" | awk '{
gsub(/M/,"",$4); gsub(/\..*/,"",$4);
gsub(/M/,"",$7); gsub(/\..*/,"",$7);
print $4, $7
}')

# Check if swap usage is high (>50% of total)
if [ ! -z "$TOTAL_SWAP" ] && [ ! -z "$USED_SWAP" ] && [ "$TOTAL_SWAP" -gt 0 ]; then
Expand All @@ -78,7 +83,9 @@ fi
log "--- Pageouts (Active Swapping) ---" "$BOLD"

if command -v vm_stat &> /dev/null; then
PAGEOUTS=$(vm_stat | grep 'pageouts' | awk '{print $2}' | sed 's/\.//')
# Case-insensitive grep matching for 'Pageouts' or 'pageouts'
# Use awk to handle parsing cleanly
PAGEOUTS=$(vm_stat | grep -i 'pageouts' | awk '{print $2}' | sed 's/\.//')
if [ ! -z "$PAGEOUTS" ] && [ $PAGEOUTS -gt 0 ]; then
log "⚠️ WARNING: Active swapping detected ($PAGEOUTS pageouts)" "$YELLOW"
log " System is using disk as virtual memory"
Expand All @@ -94,7 +101,8 @@ log "--- SSD Health ---" "$BOLD"

# Basic SMART status
if command -v diskutil &> /dev/null; then
SMART_STATUS=$(diskutil info disk0 | grep 'SMART Status' | awk '{print $3}')
# diskutil output has "SMART Status: Verified"
SMART_STATUS=$(diskutil info disk0 | awk '/SMART Status/ {print $3}')
if [ ! -z "$SMART_STATUS" ]; then
log "SMART Status: $SMART_STATUS"

Expand All @@ -117,24 +125,34 @@ if command -v smartctl &> /dev/null; then
# Get SSD wear indicators
SMART_OUTPUT=$(sudo smartctl -a disk0 2>/dev/null)

# Check for wear leveling count
WEAR_COUNT=$(echo "$SMART_OUTPUT" | grep 'Wear_Leveling_Count' | awk '{print $10}')
if [ ! -z "$WEAR_COUNT" ]; then
# Parse SMART attributes efficiently
# We want Wear_Leveling_Count (173), Reallocated_Sector_Ct (5), Media_Wearout_Indicator (169)
# The output format is: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE

# We use awk to parse everything in one pass
# Output format: WEAR_COUNT REALLOCATED MEDIA_WEAR
# Use -1 or N/A for missing values to ensure column alignment
read -r WEAR_COUNT REALLOCATED MEDIA_WEAR <<< $(echo "$SMART_OUTPUT" | awk '
/Wear_Leveling_Count/ { wc = $10 }
/Reallocated_Sector_Ct/ { rs = $10 }
/Media_Wearout_Indicator/ { mw = $10 }
END {
print (wc != "" ? wc : "NA"), (rs != "" ? rs : "NA"), (mw != "" ? mw : "NA")
}
')

if [ "$WEAR_COUNT" != "NA" ]; then
log "Wear Leveling Count: $WEAR_COUNT"
if [ $WEAR_COUNT -lt 10 ]; then
log "⚠️ WARNING: SSD wear leveling count is low" "$YELLOW"
fi
fi

# Check for reallocated sectors
REALLOCATED=$(echo "$SMART_OUTPUT" | grep 'Reallocated_Sector_Ct' | awk '{print $10}')
if [ ! -z "$REALLOCATED" ] && [ $REALLOCATED -gt 0 ]; then
if [ "$REALLOCATED" != "NA" ] && [ $REALLOCATED -gt 0 ]; then
log "⚠️ WARNING: Reallocated sectors detected ($REALLOCATED)" "$YELLOW"
fi

# Check media wearout indicator
MEDIA_WEAR=$(echo "$SMART_OUTPUT" | grep 'Media_Wearout_Indicator' | awk '{print $10}')
if [ ! -z "$MEDIA_WEAR" ]; then
if [ "$MEDIA_WEAR" != "NA" ]; then
log "Media Wearout Indicator: $MEDIA_WEAR"
if [ $MEDIA_WEAR -lt 10 ]; then
log "⚠️ WARNING: SSD media wearout indicator is low" "$YELLOW"
Expand Down
Loading