rogercorke wrote:
Well, well. I seem to have stirred up a hornet's nest here. Four replies from people - all proclaiming that moving your home folder to an external SSD will result in Armageddon.
Given that there are thousands of Mac users out there who put their home folder on an external SSD to save paying Apple's ridiculous prices for storage, would anyone who has done this like to comment?
You have been given consistent advice by highly experienced Mac users. If you want to ignore that advice, that's your choice and you accept the risk of hosing your system sooner or later.
I doubt there are "thousands of Mac users out there who put their home folder on an external SSD". But I *can* tell you we have lost count of the numbers of users who moved their home folder only to brick their Mac, lose their data and come here hoping to recover. And, sadly, many of them also never bothered to back up their data.
If you go to Settings > General > About > Storage Settings you can get a storage report about your system. And if you click the help icon (the "?") you can see Apple's definitions of the storage categories. Here is what it says about System Data:
"System Data: Contains files that don’t fall into the categories listed here. This category primarily includes files and data used by the system, such as log files, caches, VM files, and other runtime system resources. Also included are temporary files, fonts, app support files, and plug-ins. You can’t manage the contents of this category. The contents are managed by macOS, and the category varies in size depending on the current state of your Mac. You can manage your data that falls outside the other categories using the Finder or the third-party apps that created it."
In the above quote, the "don't fall into the categories listed here" refers to the other categories that are listed before System Data.
Some System Data is in your user home folder, primarily in the hidden user Library. Other System Data is in macOS itself; the system's /System and /Library folders; and the hidden volumes Preboot, Recovery & VM.
