homelab-docs/SYNCTHING.md

Syncthing Setup

Overview

Syncthing provides real-time file synchronization across all devices. Files sync automatically when devices connect.

Devices

Device	ID Prefix	Local IP	Tailscale IP	Port	Role
Mac Mini	L3PJR73	10.10.10.123	100.108.89.58	22000	Primary workstation
MacBook Pro	3TFMYEI	10.10.10.147	100.88.161.1	22000	Laptop
TrueNAS	TPO72EY	10.10.10.200	100.100.94.71	20978	Storage server (central hub)
Windows PC	YDCPUQK	10.10.10.150	100.120.97.76	22000	Windows workstation
Phone (Android)	XLMZCCH	10.10.10.54	100.106.175.37	22000	Android, Notes only, HTTPS API

Network Configuration

IPv4 Only - All devices configured with explicit IPv4 addresses (no dynamic/IPv6):

• Local network: 10.10.10.0/24
• Tailscale network: 100.x.x.x

Device address format: tcp4://IP:PORT (e.g., tcp4://10.10.10.123:22000)

Synced Folders

Folder	Path	Devices	Notes
Downloads	~/Downloads	Mac Mini, MacBook, TrueNAS, Windows	Large folder, 3600s rescan
Notes	~/Notes	Mac Mini, MacBook, TrueNAS	Documentation
Projects	~/Projects	Mac Mini, MacBook, TrueNAS	Code repositories
bin	~/bin	Mac Mini, MacBook, TrueNAS	Scripts and tools
Documents	~/Documents	Mac Mini, MacBook, TrueNAS	Personal documents
Desktop	~/Desktop	Mac Mini, MacBook, TrueNAS	Desktop files
config	~/.config	Mac Mini, MacBook	Shell configs, app settings
Antigravity	~/.gemini	Mac Mini, MacBook, TrueNAS	Gemini config

API Access

Mac Mini

API_KEY="oSQSrPnMnrEXuHqjWrRdrvq3TSXesAT5"
curl -s "http://127.0.0.1:8384/rest/system/status" -H "X-API-Key: $API_KEY"

MacBook Pro

API_KEY="qYkNdVLwy9qZZZ6MqnJr7tHX7KKdxGMJ"
curl -s "http://127.0.0.1:8384/rest/system/status" -H "X-API-Key: $API_KEY"

Windows PC

API_KEY="KPHGteJv6APPE7zFun33b3qM3Vn5KSA7"
curl -s "http://10.10.10.150:8384/rest/system/status" -H "X-API-Key: $API_KEY"

Phone (Android) - Uses HTTPS

API_KEY="Xxz3jDT4akUJe6psfwZsbZwG2LhfZuDM"
# Access via local IP (use -k to skip cert verification)
curl -sk "https://10.10.10.54:8384/rest/system/status" -H "X-API-Key: $API_KEY"
# Or via Tailscale
curl -sk "https://100.106.175.37:8384/rest/system/status" -H "X-API-Key: $API_KEY"

TrueNAS (Docker Container)

API_KEY="LNWnrRmeyrw4dbngSmJMYN4a5Z2VnhSE"
# Access via Tailscale (port 20910, not 8384)
curl -s "http://100.100.94.71:20910/rest/system/status" -H "X-API-Key: $API_KEY"
# Or via local network
curl -s "http://10.10.10.200:20910/rest/system/status" -H "X-API-Key: $API_KEY"

Note: TrueNAS Syncthing runs in Docker with:

• Config: /mnt/.ix-apps/app_mounts/syncthing/config
• Data: /mnt/vault/shares/syncthing → mounted as /data in container
• Container name: ix-syncthing-syncthing-1

Common Commands

Check Status

# Folder status
curl -s "http://127.0.0.1:8384/rest/db/status?folder=downloads" -H "X-API-Key: $API_KEY"

# Connection status
curl -s "http://127.0.0.1:8384/rest/system/connections" -H "X-API-Key: $API_KEY"

# Device completion for a folder
curl -s "http://127.0.0.1:8384/rest/db/completion?folder=downloads&device=DEVICE_ID" -H "X-API-Key: $API_KEY"

Check Errors

curl -s "http://127.0.0.1:8384/rest/folder/errors?folder=downloads" -H "X-API-Key: $API_KEY"

Rescan Folder

curl -X POST "http://127.0.0.1:8384/rest/db/scan?folder=downloads" -H "X-API-Key: $API_KEY"

Configuration Files

Device	Config Path
Mac Mini	~/Library/Application Support/Syncthing/config.xml
MacBook Pro	~/Library/Application Support/Syncthing/config.xml
TrueNAS	/mnt/tank/syncthing/config/config.xml

Performance Tuning

Speed Optimizations (2024-12-17)

Global Options

Setting	Value	Effect
numConnections	4	Parallel transfers per device
compression	never	No CPU overhead on fast LAN
setLowPriority	false	Normal CPU priority
connectionPriorityQuicLan	10	QUIC preferred on LAN
connectionPriorityTcpLan	20	TCP fallback on LAN
connectionPriorityQuicWan	30	QUIC preferred on WAN
connectionPriorityTcpWan	40	TCP fallback on WAN
progressUpdateIntervalS	-1	Disabled progress updates (reduces overhead)
maxConcurrentIncomingRequestKiB	1048576	1GB buffer for incoming requests

Applied to: Mac Mini, MacBook, Windows PC (Phone uses 512MB buffer)

Folder-Level Settings

Setting	Value	Effect
pullerMaxPendingKiB	131072-262144	128-256MB pending data buffer per folder

Applied to: downloads, projects, documents, desktop, notes folders

Rescan Intervals (set to 3600s for large folders)

Large folders like Downloads use 1-hour rescan intervals to reduce CPU usage:

• File system watcher handles real-time changes
• Hourly rescan catches anything missed

Power Optimization

From CLAUDE.md - Syncthing rescan optimization saved ~60-80W on TrueNAS VM.

Troubleshooting

Device Not Syncing

1. Check connection status:

curl -s "http://127.0.0.1:8384/rest/system/connections" -H "X-API-Key: $API_KEY" | python3 -c "import sys,json; d=json.load(sys.stdin)['connections']; [print(f'{k[:7]}: {v[\"connected\"]}') for k,v in d.items()]"

2. Check folder completion:

curl -s "http://127.0.0.1:8384/rest/db/status?folder=FOLDER" -H "X-API-Key: $API_KEY"

3. Check for errors:

curl -s "http://127.0.0.1:8384/rest/folder/errors?folder=FOLDER" -H "X-API-Key: $API_KEY"

Many Pending Deletes

If a device shows thousands of "needDeletes", it means files were deleted elsewhere and need to propagate. This is normal after reorganization - let it complete.

Web UI

Access Syncthing web interface at http://127.0.0.1:8384

SSH Access to Devices

MacBook Pro (via Tailscale)

sshpass -p 'GrilledCh33s3#' ssh -o StrictHostKeyChecking=no hutson@100.88.161.1

Check Syncthing remotely

sshpass -p 'GrilledCh33s3#' ssh hutson@100.88.161.1 'curl -s "http://127.0.0.1:8384/rest/db/status?folder=downloads" -H "X-API-Key: qYkNdVLwy9qZZZ6MqnJr7tHX7KKdxGMJ"'