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Title: What to do when a Time Machine copy to an external drive is enormously larger than expected Post by: HCK on July 09, 2020, 04:05:12 pm What to do when a Time Machine copy to an external drive is enormously larger than expected
<article> <section class="page"> <p>Time Machine uses a clever technique to make snapshots of your Mac backups. Instead of just creating copies of files that have changed since the previous backup—incremental archiving—Time Machine in macOS creates effectively a copy of each backed up volume. The clever part is that it doesn’t duplicate any file that’s remained the same between snapshots; it just adds the newly updated files.</p><p>macOS gets away with this by using “hard links,” something introduced several releases ago in which a file on a given volume can be referenced multiple times from a single central copy. It exists just once on the volume, taking up only that amount of storage. Each reference is just a few bytes. Unlike an alias in the Finder, a hard link acts to the operating system just as if it were the original file, including when it’s modified. You only wind up deleting the file if every hard link is deleted. (Essentially, deleting all but one hard link reverts it to just being a single copy of a file.)</p><p class="jumpTag"><a href="/article/3564609/what-to-do-when-a-time-machine-copy-to-an-external-drive-is-enormously-larger-than-expected.html#jump">To read this article in full, please click here[/url]</p></section></article> Source: What to do when a Time Machine copy to an external drive is enormously larger than expected (https://www.macworld.com/article/3564609/what-to-do-when-a-time-machine-copy-to-an-external-drive-is-enormously-larger-than-expected.html#tk.rss_all) |