Encrypting HFS+ external HD triggers APFS conversion, even for Time Machine drives

Originator:mike.solin
Number:rdar://36385103 Date Originated:09-Jan-2018 05:00 PM
Status:Closed Resolved:
Product:macOS + SDK Product Version:10.13.2
Classification:Crash/Hang/Data Loss Reproducible:Always
 
Summary:
On macOS 10.13.2, right-clicking on an external HD formatted as HFS+ triggers an AFPS conversion.  Once complete, the encryption will proceed.  This is is a lengthly process, and is not desirable in certain situations (such as for a Time Machine backup drive).

Steps to Reproduce:
1.  Format an external HD as HFS+.
2.  Enable Time Machine on the external HD (optional).
3.  Right-click on the external HD in the Finder, and click “Encrypt <drive name>…”

Expected Results:
4.  The drive will be encrypted.

Actual Results:
4.  The drive is converted from HFS+ to APFS.
5.  The drive is encrypted.
6.  Upon finally remounting (my 2 TB USB 3.0 drive took several days for this process to occur), you will receive a notification that a backup cannot occur, as Time Machine requires HFS+.

Version:
10.13.2

Notes:
Once following these steps, your only option is to format the Time Machine drive, losing data in the process.

Comments

Engineering has determined that your bug report (36385103) is a duplicate of 35561767 and will be closed.

By mike.solin at May 30, 2018, 3:43 p.m. (reply...)

Please note: Reports posted here will not necessarily be seen by Apple. All problems should be submitted at bugreport.apple.com before they are posted here. Please only post information for Radars that you have filed yourself, and please do not include Apple confidential information in your posts. Thank you!