My iMac computer is set to its maximum operating system Catalina and has a file system APFS.
What file system ( APFS or Mac OS Extended) should I use on my mechanical and SSD hard drive so that they both operate with time machine.
Regards,
Tony
iMac 21.5″, macOS 10.15
For format information for Time Machine external drives, see the following from: Types of disks you can use with Time Machine on Mac - Apple Support
APFS or APFS Encrypted disks are the preferred format for a Time Machine backup disk. If you select a new backup disk that’s not already formatted as an APFS disk, you get the option to erase and reformat it. If the disk is a Mac OS Extended format disk that contains an existing Time Machine backup, you aren’t asked to erase and reformat the disk.
Note: The entire APFS volume is reserved for Time Machine backups. If you want to store files other than the Time Machine backup on the same physical device, use Disk Utility to create an additional APFS volume on the disk. The two volumes then share the available space.
Time Machine still supports backups on Mac OS Extended format (Journaled), Mac OS Extended (Case-sensitive, Journaled), and Xsan formatted disks.
For format information for Time Machine external drives, see the following from: Types of disks you can use with Time Machine on Mac - Apple Support
APFS or APFS Encrypted disks are the preferred format for a Time Machine backup disk. If you select a new backup disk that’s not already formatted as an APFS disk, you get the option to erase and reformat it. If the disk is a Mac OS Extended format disk that contains an existing Time Machine backup, you aren’t asked to erase and reformat the disk.
Note: The entire APFS volume is reserved for Time Machine backups. If you want to store files other than the Time Machine backup on the same physical device, use Disk Utility to create an additional APFS volume on the disk. The two volumes then share the available space.
Time Machine still supports backups on Mac OS Extended format (Journaled), Mac OS Extended (Case-sensitive, Journaled), and Xsan formatted disks.
Sorry, the support article for Catalina is Types of disks you can use with Time Machine on Mac - Apple Support with the following excerpt rather than the one in my origin post:
The most common format for a Time Machine backup disk is Mac OS Extended format (Journaled) format, but Time Machine also supports Mac OS Extended (Case-sensitive, Journaled) and Xsan formats.
Important: You can back up from an HFS+ or APFS-formatted disk to an HFS+ disk; however, Time Machine can’t back up to an APFS-formatted disk. If you select a back up disk formatted as APFS, Time Machine offers to reformat it as HFS+.
If the disk uses the Master Boot Record (MBR) partition type, some partitions may not be available for use with Time Machine.
PS
I forgot to mention that MAC 911 states that APFS-based Time Machine backups can’t be used in Catalina or earlier releases.
Regards,
Tony
Thank you for your prompt reply to my question.
The reason for my question is that I have come across emails where people with the Catalina operating system on their computer and using APFS on mechanical and SSD external hard drives have not been able to open the files when using time machine.
So if I use APFS on mechanical or SSD external hard drives I will be able to access my files when using time machine.
Regards,
Tony
The reason for my question about the compatibility when using Time Machine with the different file systems is that
my current mechanical external hard drive is using Mac OS Extended file system. I have purchased a new SSD external hard drive. Since reading other articles regarding the use of APFS file system on SSD with Time Machine, they state that the minimum operating system on iMac has to be Big Sur.
Regards,Tony
I've not personally had any issues with an SSD external and haven't used a mechanical. I also haven't noticed any unusual number of reports of issues here in this forum.
What type of file system should External Hard Drives be set.
