Linux Format forums

GeordieJedi · Posted: Sat Feb 04, 2012 3:44 pm Post subject: Comparing 2 directories

Hi all.

I have my music collection on two hard drives (1 internal, my main master copy).
And the 2nd is on an external drive.

Now the problem is, that they are now out of sync, and I'd like to make the external drive an exact replica of the 1st internal drive.

Is there an easy way to run a comparison between the two drives?
(Possibly a GUI version)

What I'd like to achieve is -

1. To compare both directories and find the differences between them.
(If there aren't too many differences, I can manually copy across the requisite files)

2. From then onwards, I'd like to keep both dirs always synchronised.
(Something like Unison ?)

Thanks in advance for any help.

Bruno · Posted: Sat Feb 04, 2012 5:02 pm Post subject:

Unison is exactly what you need, it works like a charm. The first run can take a while but subsequent runs are very quick. If you are a subscriber, there are a few articles in back issues of the mag covering Unison.

GeordieJedi · Posted: Mon Feb 06, 2012 11:31 pm Post subject:

Cheers Bruno.

I'll check out Unison

heiowge · Posted: Tue Feb 07, 2012 8:13 am Post subject:

You could do what I do. Delete the second drive's collection, and write the other drive to it! Laughing

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Bruno · Posted: Tue Feb 07, 2012 4:26 pm Post subject:

That would work too, but it is a rather brute force method. On the second and subsequent synchronisation, Unison will only copy across the files it detects that are changed or new, which for a large collection is much more efficient. It's also convenient if each collection is independently modified (external drive is not simply a back up). You will wonder what you did before Unison after you start using it.

GeordieJedi · Posted: Tue Feb 07, 2012 7:33 pm Post subject:

Cheers Heiowge

That was my first thought. But I thought I might try and learn something instead.
If I tried to compare the directories, and then copy across the missing/different files.

I think i'll wipe the external drive. Copy the main dir over, and once they're both exactly the same
I'll then look at unison.