You may still have plenty of space on your backup volume, but if it has millions of files and hard links from years of backups, it will be very slow. Here’s how to fix that.
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The High Sierra upgrade did not go well for many users. Here are some of the reasons why macOS 10.13 is currently a lemon.
Time Machine diagnostics now available for Sierra, and (in beta) for High Sierra.
Explains how Time Machine knows what to back up, why it performs deep event scans, and how that system is different from HFS+ journaling.
A strange problem with backups that start, but fail to complete successfully, apparently because of duplicate filenames. T2M2 to the rescue, bringing some important lessons.
Scheduling background activities like making backups has moved from cron to launchd, and now to a more complex system. This has reduced the reliability of macOS and made it harder to support.
Different search and filter tools have different purposes – as demonstrated by exploring the log using Consolation 3. Regex at work!
Automatic backups will still become irregular or fail altogether, making Sierra 10.12.6 unsuitable for servers and systems requiring sustained operation.
How to diagnose this bug, manage it when it occurs, and try to prevent it from happening: latest information.
Apple now states that APFS will handle the problems of normalisation of file and folder names. At least in iOS 10.3.3 and macOS 10.12.6, due shortly.
The Eclectic Light Company 