MacOS

ISSUE

Every good storage failure starts innocently.

Plug in a brand-new Samsung T7.
Select it in Time Machine.
Click “Use Disk.”
Allow macOS to format the drive automatically.
Let the backup run. It may even complete once — maybe even a few more times.
Then it fails with a generic error:
“An error occurred while preparing the backup.”

Time Machine consistently failed during the “Preparing backup” phase on macOS 26.3 (Tahoe).

Date: 2026-02-10
Host: new Mac (macOS Tahoe)
Context: Migration Assistant clone from older Mac failed

Summary

First day using macOS Tahoe, immediately greeted with a broken Migration Assistant clone from an older Mac. The system failed to reach the login window due to a corrupted SecurityAgent authorization plugin left behind by TeamViewer. This caused login to fail and wedged Setup Assistant in a deadlock during post-migration initialization.

Introduction to Setting Up Unbound (Sinkhole) on a Mac

This guide shows you how to set up Unbound on your Mac with MacPorts. Unbound is a validating, recursive, and caching DNS resolver. The primary goal is to create a DNS sinkhole. A DNS sinkhole is a security mechanism that intercepts and blocks malicious traffic. When you configure Unbound on your Mac, you improve your network security. You also enhance privacy with DNS over TLS. You block unwanted ads and trackers.

Date: 2026-02-08
Host: macOS (MacPorts prefix: /opt/local)
Component: doas (MacPorts)

My WireGuard client app failed to load profiles because the code path relies on doas for privilege escalation. This fix corrects the macOS (MacPorts) doas installation so the client can elevate properly.

doas: not installed setuid

…and exiting with status 1.

Root Cause

On macOS, MacPorts installs doas without the setuid bit by default.

Because doas is not setuid-root, it cannot elevate privileges. I depend on doas and rarely use sudo, so any command that relies on it fails immediately, including:

Date: 2026-02-08
Host: server (macOS Monterey; Homebrew prefix: /usr/local)
Grafana install: Homebrew (/usr/local/opt/grafana)
Grafana data: /usr/local/var/lib/grafana

Grafana (Homebrew on macOS Monterey) & Password Reset + Boot-Time Startup (No GUI Login)

Summary of the fix

1. The admin password did not work, even after reset attempts.
2. Grafana ran manually, but it did not run reliably as a user service through brew services. The service needed to start at boot without a desktop login.
3. We fixed both problems:

• Reset the password against the actual Brew paths and database that the running server uses.
• Replace the GUI-bound LaunchAgent approach with a system LaunchDaemon at /Library/LaunchDaemons/... that runs at boot as your user.

Caveats

The password reset reported success but used the wrong database

You can point Grafana at different data directories. In this setup, the running Brew Grafana server uses: