I use time machine but weekly and before upgrading I make an image backup. I use the Disk Utility for this but I find some options don’t work.
I go to File->New->Disk Image from disk0s2 (Macintosh HD)..
A dialog opens that says SaveAs: Macintosh HD
The drive selected is my BackUp drive and I can see all the files. I click on save> I am asked for my password and I enter it and another dialog says creating image “Macintosh HD.dmg” but then I get an error saying it can’t create “Macintosh HD”. (resource busy). This is nonsense since my backup drive does nothing but backups. It would seem this would be the easy way to backup a drive but it never works. Instead I must
File->New-Disk image from folder. Then I selecth the Macintosh HD everything works.
Windows Backup is much easier to use and provides many more options as to what is backed up.
A big fail whale for Apple disk utility up.
— Peter Nachtwey