Hey, I'm trying to erase free space on main volume using diskutil secureErase freespace command, but I'm getting "Erasing freespace only works on mounted and writable volumes". Any ideas please?
MacBook Pro 13", macOS 10.15
Another possibility is you are using an SSD. Disk Utility does not allow a Secure Erase on an SSD because it doesn't do any good because of the way SSDs work internally and it just causes unnecessary wear on an SSD. If you are using an SSD, then the blocks where the deleted data was stored will automatically be erased once TRIM works on the now discarded block or the discarded block is processed by the SSD's internal garbage collection routines.
If the computer is using FileVault, then no one will be able to see the deleted data anyway unless they were able to unlock the FileVault.
Another possibility is you are using an SSD. Disk Utility does not allow a Secure Erase on an SSD because it doesn't do any good because of the way SSDs work internally and it just causes unnecessary wear on an SSD. If you are using an SSD, then the blocks where the deleted data was stored will automatically be erased once TRIM works on the now discarded block or the discarded block is processed by the SSD's internal garbage collection routines.
If the computer is using FileVault, then no one will be able to see the deleted data anyway unless they were able to unlock the FileVault.
I've no experience with diskutil secureErase. Anyway, Catalina separates the partition where it resides in two volumes (well, actually more than 2 as you can see from your terminal screenshot): Macintosh HD and Macintosh HD – Data. The latter is where your information (as a user) is stored. Maybe you have to work only on that partition, because the former is read only (for the end user) for security purposes.
Yeah, my Mac has both SSD and FileVault activated. Thanks for your reply.
Terminal - diskutil secureErase freespace not working
