{"id":77657,"date":"2021-09-15T13:30:00","date_gmt":"2021-09-15T18:30:00","guid":{"rendered":"https:\/\/eshop.macsales.com\/blog\/?p=77657"},"modified":"2021-09-15T13:09:42","modified_gmt":"2021-09-15T18:09:42","slug":"the-issues-with-macos-big-sur-time-machine-hfs-volumes-and-apfs","status":"publish","type":"post","link":"https:\/\/eshop.macsales.com\/blog\/77657-the-issues-with-macos-big-sur-time-machine-hfs-volumes-and-apfs\/","title":{"rendered":"The issues with macOS Big Sur, Time Machine, HFS volumes, and APFS"},"content":{"rendered":"\n

If you’ve updated to Big Sur and notice that you no longer see one of your Time Machine volumes, it didn’t disappear. Chances are your volume was HFS+, or some other incompatible format. Here’s the background.<\/p>\n\n\n\n

About APFS<\/h2>\n\n\n\n

APFS is the default file system in macOS High Sierra and later for Macs with all-flash storage. I\u2019m guessing this will hold true when macOS Monterey<\/a><\/strong> is released. APFS features strong encryption, space sharing, snapshots, fast directory sizing, and improved file system fundamentals.<\/p>\n\n\n\n

When you install macOS High Sierra and later on the built-in solid-state drive (SSD) of a Mac, that drive is automatically converted to APFS. Fusion Drives and hard disk drives (HDDs) aren\u2019t converted.\u00a0You can\u2019t opt-out of the transition to APFS. If you install APFS on any<\/em>\u00a0Mac that uses a solid-state drive (SSD) as a built-in boot drive, it will automatically convert to APFS and you will not<\/em> have a choice. Older Macs that use Fusion Drives or regular hard disk drives (HHDs)\u00a0will not<\/em>\u00a0be converted.\u00a0<\/p>\n\n\n\n

Apple has promised APFS support for Fusion Drives, but, as best I can tell, this hasn\u2019t happened yet. And no new Macs ship with a Fusion Drive. (By the way, a Fusion Drive was a storage option on some iMac and Mac mini computers that combined a hard drive and flash storage in a single volume.)<\/p>\n\n\n\n

With macOS Big Sur, you’ll need a drive formatted with APSF (Apple File System) to use Time Machine for backing up your files (and you really should be backing up your files<\/a>). If you have existing HFS volumes, you won\u2019t see them after you update, so you shouldn\u2019t update any such volumes.\u00a0<\/p>\n\n\n\n

Why? There\u2019s no way to convert an HFS+ Time Machine volume to one that uses APFS without erasing it. <\/p>\n\n\n\n

As noted by Macworld<\/em><\/a>, before you format a Time Machine drive to APFS, you should note that your old HFS+ based Time Machine volumes remain valid and readable in Big Sur. You can set up a drive from scratch with HFS+ to create new Time Machine volumes as well.\u00a0<\/p>\n\n\n\n

However<\/strong>\u2014and this is the big \u201cgotcha\u201d\u2014if you want to shift a drive from HFS+ to APFS, you have to reformat the drive. That erases all the Time Machine backups. Macworld<\/em> notes that, because of the structural differences, you can\u2019t just copy from HFS+ to APFS, either.<\/p>\n\n\n\n

The article also points out that:<\/p>\n\n\n\n

\u00b0\u00a0Big Sur APFS-based Time Machine backups can\u2019t be used in Catalina or earlier releases. This probably only affects a handful of people, but you\u2019ve been warned.\u00a0<\/em><\/p>\n\n\n\n

\u00b0\u00a0You can share the Time Machine container with volumes that aren\u2019t being used for backups.<\/em><\/p>\n\n\n\n


Apple’s recommendation<\/h2>\n\n\n\n

Apple recommends that you work with file formats that work with the company\u2019s Disk Utility. This makes sense as that\u2019s likely the tool you\u2019ll use when formatting, diagnosing, etc., any Mac drives. <\/p>\n\n\n\n

In a support document<\/a>, Apple says that you should choose one of the following APFS formats for Mac computers using macOS 10.13 or later.<\/p>\n\n\n\n