Any idea what "Volumes" is on my iMac HD?
I recently noticed that the hard drive (3 TB fusion drive) on my late 2015 27" iMac (macOS 11.1) was more full that it should be (pre-dates the Big Sur update). When I ran Daisy Disk as Administrator, I found something odd. The top level of the HD has the usual 4 folders: Applications, Library, System, and Users. But it also had a folder (not visible in the Finder) called "Volumes," and in that is another folder called "iMac - Data," and in that are the same 4 folders that exist at the top level of the drive: Applications, Library, System, and Users. This mystery "Volumes" takes up ~1 TB vs. ~1.4 TB for the rest of the drive.
What is this "Volumes," an apparent partial duplicate of the rest of my hard drive? How do I get rid of it or at least shrink it?
Appreciate any insights. Thanks!
If you are using Time Machine as a backup, then the recommended size is 3 times the amount of space you want to backup, so that you have ample room to keep older copies and thus go back in time several months (even years) to older copies of a file.
If you are just going to make a clone, then you need a backup devices that is at least as large as the amount of data you current have.
As to 'other volumes' I do not know every hidden file on macOS. But I would again caution you to be careful about deleting files are are not in your home folder, and even in your home folder, I would be very careful about deleting things in your home folder -> Library subfolder, as the Library subfolder has things like your email, iPhone backups, preferences, Notes, etc...
For performance, mostly you need the SSD to hold the operating system, the applications, and it would be good to hold the non-huge items from your home folder.
iTunes, Photos, iMovie can all point to another device for the big stuff. There are webpages with instructions on moving these library to another device, and getting the apps to look on that device for the content.
If you have huge file content that is not managed by an app with the ability to point to an external device, you would figure this out based on the app that uses those files.
So you could most likely get away with a 512GB or 1TB SSD for the boot device, and then keep all the bulk storage on the Fusion drive.
If you do not want to deal with splitting your files into 2 different devices, then get a 3TB (or larger SSD) and use something like Carbon Copy Cloner to move your bootable system to the new external SSD.
If in your Daisy Disk explorations, you have found files in you home folder that are wasting space, then by all means free that space up, as long as you know it is a file you created, or downloaded, and no longer need it anymore.
And DO NOT assume that if the file is on Time Machine you can delete it. Time Machine is a backup of your current files. It is not an archive, even if it will keep old copies. Eventually Time Machine will delete old copies when they age out several months.