How do you create a bootable back up of the hard drive w/ disk utility?

Question

I think it's pretty incredible that the most basic of basic topics, how to create a back up of your hard drive using the native software Disc utility, is nowhwere to be found. I tried searching "create bootable back up" and amazingly enough nothing comes up. Anyway.... can anybody let me in on this top secret information, I would really appreciate it. Once again the objective is to make a bootable clone of my hard drive onto an external disk. Thanks for the help,
-BK

Answer 1

    Are you saying I could still use Disk Utility's Restore function to clone a 90GB startup drive, that had 40GBs used, to a clean 60GB backup drive?
Correct. The size of the source drive is completely irrelevant – as Kappy is saying, it's just the size of the data to be copied that counts. (An explanation that some people like is that "empty space is not copied").
    I've always used a dedicated backup drive that was larger than my startup drive
Nothing 'wrong' with that, but unnecessary. Same size would be large enough for any future possibility. Theoretically, if you had a 250GB internal drive but knew that you would never have more than 20GB of data on it, a 40GB backup drive would be considerably more than sufficient (a bit of a silly example, but true). Other considerations: 1. you already know about the 15% free space recommendation, and 2. with drives, 'bigger' is nearly always a better investment for the future. I would always advise someone about to buy a drive to multiply the size they were thinking of by at least 4.
    always reformatted and zeroed it
Again not 'wrong', but overkill. A simple 'erase' (2 seconds) would suffice – erased is 'clean' enough. Consider that those, like myself, who do "synchronized" backups (copying only added or changed items for the saving of time) NEVER erase the target, or just once in a blue moon. If your backup drive is stationary on your desk the chances of it developing another bad block are close to nil. The time when a re-zeroing (mapping out of bad blocks) becomes imperative is immediately after the cat knocked the drive onto the floor! We are in the main talking here about a software solution (the mapping) of a hardware problem, physical imperfections on the surface of the disk.
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Regarding 'other stuff' on the backup/target drive, our suggestion for CCC users is:
[Note that this is NOT for the situation where the target is to be erased every time.]
    For your first cloning you should find a temporary home for that stuff on the external drive so that you can prepare the drive correctly [instructions…] After that you can move that 'other stuff' back onto the external drive.
    If you absolutely cannot find the needed 'temporary home' you can proceed anyway but you must take responsibilty for any consequences due to inadequate preparation of the drive (e.g. not 'zeroing' it to map out any bad blocks) – you should be OK but it is a question of luck. For subsequent clones, and for this first one if you wish to proceed, you do not need to move that 'other stuff' if you do as follows…
    You have to ensure that the clone will not interfere with that other stuff. Put all that 'other stuff' into a folder (with sub-folders as you desire) on the target (at root level, i.e. what you see when you dbl-click on the disk icon) and give that folder a unique name, i.e. a name which you know you will never use on your source drive. If you did have such a folder on the source the cloning would make the folder on the source overwrite the one on the clone, so choose the name with some thought. (How about: "Nevercall_methis"? ;=))
A dedicated backup drive is, beyond doubt, to be highly recommended as the best arrangement. 'Other stuff' on that drive is possible, easily 'do-able', but is often the cause of complications at some stage. (Buy another drive! ;=)).
"Buy another drive" is not just me being facetious. If you data is vital to you, you should have TWO backups on different drives. Consider this: while you are cloning/backing up, you actually have NO backup – a power outage and all, source and backup, could be lost at the same time – unlikely but not impossible. I do hate to be a harbinger of gloom, but…
Happy cloning!  ;=)
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