Re: A good encryptor for old Mac OS X 10.2.8?

On Tue, 17 Jun 2008 23:01:58 GMT, me@[EMAIL PROTECTED]
 (Király) wrote:

>In comp.sys.mac.system Howard Brazee <howard@[EMAIL PROTECTED]
> wrote:
>> So if I have my encrypted dmg file, I can tell Time Machine to go
>> ahead and back it up, and it will automatically not fill up every time
>> I change a file within it?   Nothing for me to do?
>
>If your image is a sparse *bundle*, then yes.  
>
>I have a sparse bundle that is 1.27GB in size.  Inside are 87 or so 
>bands (files) of 16MB each.  If I add another 10MB of data to the 
>image, just one of those bands gets modified, and/or one more band gets 
>created.  The rest of the bands remain intact.  So the next time Time 
>Machine runs, it only needs to add the changed and/or new bands to the 
>TM backup disk.  If this were a regular disk image, TM would add the 
>whole 1.27GB image file over again.
>
>You should be able to convert your regular sparse image to a sparse 
>bundle with Disk Utility's Images -> Convert menu item.  Or, create a 
>new empty sparse bundle, move your files to it, and delete your old 
>image.

Get Info didn't tell me anything about "sparse", so I'm guessing my
..dmg file is neither.   I never heard of that word with regards to OS
X before this thread.   I did look up "sparse" in _Mac OS X: The
Missing Manual_, and see that I could have created it with either
option.  I suspect I did so with neither option (or else I'd see it in
Get Info).

It doesn't explain when I would want a sparse image, a sparse bundle
disk image, or just a read/write disk image.