Advanced Example: Optimized Configuration
Power-user configurations for specific scenarios.
Scenario 1: Developer Workstation
System: 16 GB RAM, NVMe SSD, heavy IDE usage
Goals:
- Prioritize development tools
- Fast VS Code and browser loading
- Minimal overhead since SSD is already fast
Configuration
# /etc/preheat.conf - Developer Workstation
[model]
# Slightly less frequent since SSD is fast
cycle = 25
# Use correlation for better predictions
usecorrelation = true
# Track smaller apps too
minsize = 1000000
# Moderate memory usage (SSD benefit is smaller)
memtotal = -10
memfree = 40
memcached = 0
[system]
doscan = true
dopredict = true
autosave = 3600
# No sorting needed for SSD
sortstrategy = 0
# High parallelism (SSD handles it)
processes = 50
# Path filters
mapprefix = /usr/;/lib;/opt/;/var/cache/;!/
exeprefix = /usr/;/opt/;!/
# Whitelist common dev tools
manualapps = /etc/preheat.d/dev-apps.list
Whitelist File
# /etc/preheat.d/dev-apps.list
# Priority development tools
# Editors
/usr/bin/code
/usr/bin/vim
/usr/bin/nvim
# Browsers (for testing)
/usr/bin/firefox
/usr/bin/chromium
# Development tools
/usr/bin/docker
/usr/bin/git
/usr/bin/node
/usr/bin/python3
Scenario 2: Low-Memory Laptop
System: 4 GB RAM, HDD, general use
Goals:
- Conservative memory usage
- Don’t compete with applications for RAM
- Maximize HDD benefit
Configuration
# /etc/preheat.conf - Low Memory System
[model]
# Less frequent to reduce overhead
cycle = 30
usecorrelation = true
# Only track substantial applications
minsize = 5000000
# Very conservative memory usage
memtotal = -25
memfree = 20
memcached = 0
[system]
doscan = true
dopredict = true
# Less frequent saves
autosave = 7200
# Block sorting critical for HDD
sortstrategy = 3
# Limited parallelism
processes = 5
# Minimal paths
mapprefix = /usr/;/lib;!/
exeprefix = /usr/;!/
Scenario 3: Security/Pentesting Workstation
System: Linux with security tools, HDD
Goals:
- Preload common security tools
- Learn pentesting workflow patterns
- Handle large tools like Burp Suite
Configuration
# /etc/preheat.conf - Kali Security Testing
[model]
cycle = 20
usecorrelation = true
minsize = 2000000
# Moderate memory (leave room for VMs)
memtotal = -15
memfree = 40
memcached = 0
[system]
doscan = true
dopredict = true
autosave = 3600
sortstrategy = 3
processes = 20
# Include Kali tool paths
mapprefix = /usr/;/lib;/opt/;!/
exeprefix = /usr/;/opt/;!/
# Security tools whitelist
manualapps = /etc/preheat.d/kali-tools.list
Whitelist File
# /etc/preheat.d/kali-tools.list
# Security tools priority list
# Browsers
/usr/bin/firefox-esr
# Terminal tools
/usr/bin/tmux
/usr/bin/zsh
# Common assessment tools
/usr/bin/nmap
/usr/bin/gobuster
/usr/bin/sqlmap
# Note: Burp Suite will be auto-learned
# if you use it frequently
Scenario 4: Monitoring Without Preloading
Use case: Learn about your application usage without preloading.
Configuration
# /etc/preheat.conf - Monitor Only Mode
[model]
cycle = 20
minsize = 1000000
[system]
doscan = true
dopredict = false # Learn but don't preload
autosave = 1800 # More frequent saves for data collection
Analysis
After running for a few days:
# Dump comprehensive statistics
sudo preheat-ctl dump
sudo tail -200 /usr/local/var/log/preheat.log
# See what would be predicted
# Look for "tracked applications" entries
Creating a Custom Whitelist
Step 1: Identify Your Top Applications
# What are you running most?
# (Run this over a few days)
grep "tracked applications" /usr/local/var/log/preheat.log
# Or check history
history | awk '{print $2}' | sort | uniq -c | sort -rn | head -20
Step 2: Find Full Paths
which firefox
# /usr/bin/firefox
which code
# /usr/bin/code
Step 3: Create Whitelist
sudo mkdir -p /etc/preheat.d
sudo nano /etc/preheat.d/apps.list
Add one path per line:
/usr/bin/firefox
/usr/bin/code
/usr/bin/thunderbird
Step 4: Enable in Config
[system]
manualapps = /etc/preheat.d/apps.list
Step 5: Reload
sudo preheat-ctl reload
Creating a Blacklist
Use Cases
- Exclude large games (too slow to preload)
- Exclude broken applications
- Exclude sensitive applications
Steps
# Create blacklist
sudo nano /etc/preheat.d/blacklist
# Applications to never track
/usr/games/heavy-game
/opt/problematic/app
Enable in config:
[preheat]
blacklist = /etc/preheat.d/blacklist
Performance Monitoring Script
Create a script to monitor preheat effectiveness:
#!/bin/bash
# /usr/local/bin/preheat-stats
echo "=== Preheat Statistics ==="
echo
# Status
if sudo preheat-ctl status > /dev/null 2>&1; then
echo "Status: Running (PID $(cat /run/preheat.pid))"
else
echo "Status: NOT RUNNING"
exit 1
fi
echo
# Memory
echo "Daemon Memory:"
ps -o rss,vsz,pmem -p $(pidof preheat) | tail -1 | \
awk '{printf " RSS: %.1f MB, VSZ: %.1f MB, %%MEM: %s\n", $1/1024, $2/1024, $3}'
echo
# State file
echo "State File:"
ls -lh /usr/local/var/lib/preheat/preheat.state 2>/dev/null | awk '{print " " $5}'
echo
# Activity
echo "Recent Activity:"
sudo grep "running processes" /usr/local/var/log/preheat.log | tail -5 | \
awk '{print " " $0}'
echo
# Uptime
echo "Daemon Uptime:"
ps -o etime -p $(pidof preheat) | tail -1 | awk '{print " " $1}'
Make executable:
sudo chmod +x /usr/local/bin/preheat-stats
Use:
sudo preheat-stats
Integration with Shell
Automatic Dump Before Shutdown
Add to /etc/rc0.d/K01preheat:
#!/bin/bash
preheat-ctl save
Alias for Quick Status
Add to ~/.bashrc or ~/.zshrc:
alias pstatus='sudo preheat-ctl status'
alias pdump='sudo preheat-ctl dump && sudo tail -100 /usr/local/var/log/preheat.log'
Best Practices Summary
| Scenario | Key Settings |
|---|---|
| HDD system | sortstrategy = 3, processes = 20 |
| SSD system | sortstrategy = 0, processes = 50 |
| Low RAM (<4GB) | memfree = 20, memtotal = -25 |
| High RAM (>8GB) | memfree = 60, memtotal = 0 |
| Predictable workflow | Default config, add whitelist |
| Unpredictable workflow | Consider not using preheat |
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