The title says it all. While AFP had been officially deprecated, it still continued to be included right through Catalina.
Big Sur changes that, the long unmaintained afp is gone, with SMB being the only native file-sharing (as a server) option. SMB 3 is the default version.
This will affect network shares and especially Time Machine. Many of us stuck with afp for Time Machine compatibility, but if you haven't already made the switch to smb, best to do it before upgrading to Big Sur to avoid compatibility problems.
New network TM destinations are still created with a sparsebundle, however it is now APFS rather than HFS+ formatted internally. Existing HFS+ sparesebundles will still work and are not converted to APFS. Backup performance is dramatically improved as the APFS makes use of snapshots for each backup. In other words, your TM backups via SMB from Catalina should continue to work, but won't have the speed advantages unless one creates a brand new backup destination.
Big Sur changes that, the long unmaintained afp is gone, with SMB being the only native file-sharing (as a server) option. SMB 3 is the default version.
This will affect network shares and especially Time Machine. Many of us stuck with afp for Time Machine compatibility, but if you haven't already made the switch to smb, best to do it before upgrading to Big Sur to avoid compatibility problems.
New network TM destinations are still created with a sparsebundle, however it is now APFS rather than HFS+ formatted internally. Existing HFS+ sparesebundles will still work and are not converted to APFS. Backup performance is dramatically improved as the APFS makes use of snapshots for each backup. In other words, your TM backups via SMB from Catalina should continue to work, but won't have the speed advantages unless one creates a brand new backup destination.