I did something stupidish

Question

I recently updated my Macbook Air to Mavericks. I figured I should make a backup before I did that. So I used an external drive that I had been using to store some data at the root level — almost 200 GB of data. I used Carbon Copy Cloner to make the back up and there was a choice to not delete anything that may already be on the external drive, so I selected that.
That left the folder of my data at the root level and the regular structure you would see at the root level of a Mac boot volume — System, Runtime, Library, Users, etc. And it is a bootable clone, I was able to boot up and run my old system from the external hard drive.
However I can add anything else to the folder, let's call it Google Books Ngrams folder. I tried downloading data to the folder using Chrome and it just tells me the download failed. I downloaded files to my internal drive and tried to copy them over but it tells me "The operation can't be completed because an unexpected error occurred (error code -50)."
I'm guessing it is some kind of permissions thing? Any idea what I can do to make it so I can download more data to that folder? I really don't want to have to start again. Thanks.

Answer 1

Using finder, go to the external drive and right click on the folder in question.  Now do a "get info" and at the bottom will be the permissions.  If you have an administrator account (and you should), you can unlock the padlock for changes.  Add yourself as Read and Write.  Add staff as Read and Write.  Add everyone as read only.  Wheel and Root should not be listed for that folder since it is for personal files.  There is a little wheel icon that can change the permission inside recursively.
That is what I would do.
Others may have different opinions.