Transferring Data from Mac to Ubuntu

How are you attempting to perform the copy? You may want to try running the application you're using for copying the files as root. So, if it's the regular file browser, you can do this by pressing Alt+F2 and running:

gksu nautilus

Then try doing the copy. The files might have the wrong permissions when they arrive on the destination ext4 drive, but you can always change that.

When you're done, you should close this root Nautilus window, so you don't confuse it with regular Nautilus windows, which could result in you accidentally messing things up bad in your system.

If that doesn't work, please post a reply. But either way, you should be aware that a copy operation will probably not preserve files' resource forks (see http://en.wikipedia.org/wiki/Resource_fork and http://linuxmafia.com/faq/Filesystems/hfsplus.html). This might not be a problem--if this was an external drive, never used to store applications, and never used to store old files or files created by old (Classic Mac OS) applications, then you're probably fine with a simple copy. But if you need to retain resource forks and/or achieve the completely separate goal of keeping the drive bootable (i.e., if this is a drive that an operating system is installed on), then you may be better off imaging the drive rather than copying its contents. (Besides "data forks", which are treated as "the file", and resource forks, HFS+ also supports named forks, similar to Alternate Data Streams in NTFS. See http://en.wikipedia.org/wiki/Fork_(filesystem). But these are rarely used--it's probably not a problem that they would likely not be copied either.)

This is great! Thanks so much for your informed response. How can I close gksu nautilus when I am done? Will I close this program by simply x'ing out? Should I restart?

Re resource forks, I do not have any applications. Nor are there any old files or files created by old Mac applications. I do have very old Windows files (mostly MS documents) but nothing Mac older than 2005.

"How can I close gksu nautilus when I am done? Will I close this program by simply x'ing out?"

Yes, that's all that's necessary. Just close the window.

You should be aware, however, that if you launch other windows, or other applications, *from* that root Nautilus window, then they, too, will be running as root.

"Should I restart?"

No, that would be quite unnecessary.

Thanks Eliah Kagan, that solved my question.

So now I don't have the right "permission" for some of the folders I was able to copy to my ext4 external HD. The system says that the permission belongs to the root. How can I take the permission back now?

In a root Nautilus window (if you close the one from before, just run "gksu nautilus" again), right-click on a file or folder, click Properties, click the Permissions tab, then you can change the ownership and permissions. If it's a folder then you can, if you wish, change the permissions for all the enclosed files (by making them what you want for the enclosing folder, then clicking the "Apply Permissions to Enclosed Files" button). You'll probably want to change the owner for all the files from root (or whatever it is currently) to yourself, and to change the group (a.k.a. group owner) to your primary group (which by default in Ubuntu is the group with the same name as your username). Ownership changes get applied to all of a folder's enclosed files too, when you the aforementioned button.

One thing: I recommend not changing the "Allow executing file as a program" permission. This is not something you want enabled for most files. One of the reasons for that is that doing so tends to have the effect of confusing non-program files with programs (for the user). But also, it's good to have to take an extra step to mark a file executable before running it as a program (i.e., this is intended as a security feature).

Thanks this has been helpful. Thank you so much! Now I have access to all folders and files.

I have just double checked whether I have copied everything into the new external hard drive. The strange thing is that the ext4 hd tells me that I have 396,025 items in 62 folders totaling 509.5 GB. The Mac external drive on the other hand tells me that I have 393,639 items in 62 folders totaling 552.43 GB. How can I make sense of these numbers? Why do they not match except in folder numbers?

You should check to make sure that you have access to all the folders on both drives--if you don't a comparison operation might not be correct, because it would not take information into account that it is unable to obtain. Alternatively, you could run a root Nautilus window (gksu nautilus) and use that to perform the comparison. Perhaps that is what you did. If such permissions issues don't account for the discrepancy, then were probably files that did not get copied. I don't know why.

If you've ruled out permissions issues as described above, then I recommend you proceed check for the most obvious causes of files not being copied.

In Ubuntu (and also in Mac OS X), files and folders that start with a . (dot) are not shown by default when examining the contents of folders. These entries should be accounted for when you get statistical information on a folder that contains them. But if you selected all the visible entries in, say, the root folder of the Mac hard drive, and copied those files to the ext4 volume, there may have been other entries (files, folders, or both) that you didn't select, because you didn't see them, because they started with a dot.

Files starting with a dot are rarely large. Folders starting with a dot occasionally contain large files, but most often they don't. So I'm not at all sure that this is what accounts for your problem, but it's the most obvious solution, which I think should be examined first.

To examine these files, click View > Show Hidden Files. (To reverse this setting, click it again to uncheck it.) Again, please note that if you copy a whole folder, it should have copied all the files and folders contained within that folder, so it's only files and folders in the *root* of the copy operation (which I am guessing was the root of the Mac hard drive) that you need to check against the files and folders wherever you copied them.

If that turns out not to account for the discrepancy, please post another reply and we'll keep investigating the matter.

You were quite right! Apparently when I was reading the numbers I gave earlier, I was not signed in as root. Once I signed in as root, all numbers matched. So I call this operation a success and I am very grateful for your support and help.

I love Ubuntu more than ever. And I am happy I made a switch from Mac.

Thanks once again for your informed comments.

Ron

When you talk about being "signed in as root" I presume you mean "running Nautilus as root." (On some other operating systems, like Fedora, and even on Ubuntu if you make a configuration change which is **not recommended**, it is possible to actually log in as root. In Ubuntu, running specific programs as root with sudo, or with graphical frontends to sudo like gksu, is considered a better way to perform administrative tasks.)

I'm glad the copy operation was successful and that Ubuntu is working well for you!

You can try to use GBCopy to copy. It will help you copy everything across platforms very easy and simple.