Why does my new APFS case insensitive backup drive get changed to case sensitive by Time Machine?
iMac Line (2012 and Later)
TM only sets itself to case sensitive just incase your drive is case sensitive. it will not affect the function of TM, regardless of how your local drive is set.
Additional information: none of the volumes being backed up by Time Machine is case sensitive... so this is not a situation where the OS changes the ** drive to match... it changes it to NOT MATCH that parameter.
Thank you!! I was not aware of that, so was surprised when it happened. Apple recommends against using the "case sensitive" param unless you know what you're doing. But, if they are going to OVERRIDE the settings deliberately specified by the owner of the equipment, they owe their customer a heads up in a pop up!!!
I had deliberately erased my Time Machine and re-formated it "case insensitive" When I noticed later that it was "case sensitive" --- I assumed I had been careless when I formatted it months ago. So I wasted a lot of time re-formatting and starting a new Time Machine backup and also lost previous backups. Imagine my surprise when I saw it was case sensitive again... thought I was loosing it... but turns out it's Apple that's loosing it. Their kids who play with the software need adult supervision :-)
Time Machine drive format
