Which disk format for TimeMachine in macOS High Sierra?

[Dr.SL]

Hi,
as High Sierra introduces the APFS disk format, will be this format mandatory also for TimeMachine?

 

[KALLT]

The Time Machine disk itself must be HFS Plus for the time being. APFS does not support directory–directory hard links which Time Machine builds upon. Your Macintosh HD can be APFS, doing so will give you access to a new local snapshots feature.

 

[Dr.SL]

OK?!

 

[AlanShutko]

The Time Machine disk itself must be HFS Plus for the time being. APFS does not support directory–directory hard links which Time Machine builds upon. Your Macintosh HD can be APFS, doing so will give you access to a new local snapshots feature.

Time Machine uses the directory hard links in order to share directories between backup sets. I suspect that it will be changed to use APFS snapshots instead, when Time Machine adds support for APFS.