Need help


I am still somewhat new to Mac and have loved every minute of it. I have just recently encountered a problem that I do not know how to solve.

Here is the problem.

I have to different external hard drives. One is currently being used everyday and the other one was used to back up data a month or so ago. What I need to figure out is how to merge the data within both drives onto one drive. If it sounds confusing let me try to better explain.

Drive A is in current use. It has a file system similiar to drive b except drive A has some newer files as does drive B that either may not have.

example. Drive A has a file named File 1 that contains Documents A,B and C and File 2 that contains Documents L and P

Drive B has same File 1 but contains Documents D,E and F as well as File 2 but contains Documents X and Z.

How can I merge the data from Drive B File 1 into Drive A File 1 without losing the data from Drive A File 1 so that it becomes Drive A File 1 containing Documents A,B,C,D,E and F as well as File 2 containing Documents L,P,X and Z.

I have tried to copy by dragging from drive B to drive A but it wants to overwrite or replace the data rather than just copy or add the files not currently found within the folders.

I apologize upfront if this sounds confusing but I had no other way of explaining. I have dozens of folders that are the same on each drive and dread having to go into each one individually to drag files across.

Any help or advice is greatly appreciated.

Thanks and have a good weekend.


You should look for a backup software

you will find some good suggestions here

I would also suggest you to use the search feature of the forum to find answer(s) that might very well do for your question(s)

Have a great week-end too :)


Staff member
I guess by 'file' you mean folder (also known as directory), and by 'document' you mean file. Instead of selecting a folder and moving it to the location where a folder of the same name exists, simply select the _files_ within the folder and drag them over the folder you want to put them into. This way, the Finder only asks you what to do with _documents_ (files) of the same name instead of everything (i.e. the folder).


One more, for the road!
There is software available from.

The program that will help you is called "You Syncronize"
it has among it's 3 sync modes one called "two way syncronize", which, if I read your problem correctly, is exactly what you're looking for.
They offer a free trial which might be all you need.



Thanks for the suggestions, I bought the Chronosync and all my problems are now solved!

Thanks again and I hope everyone has a great weekend!