During upload I get a message: could not rename file from /tmp to public/1/17/ggg.jpg

[saariko]

So I got this error, the solution was to chmod 777 directory 1/17 under images.

However, my question is: will this happen frequently now? how come this happens at all?

Do I need to change permissions?
Who is the user who is doing the upload file? maybe all I need is to change that?

[saariko]

Checking the file, it seems that the user that uploads the file is: nobody
Can that be changed?

[hoggwild]

So I got this error, the solution was to chmod 777 directory 1/17 under images.

However, my question is: will this happen frequently now? how come this happens at all?

Do I need to change permissions?
Who is the user who is doing the upload file? maybe all I need is to change that?

You are getting this error because the permissions on the "images" directory, where the uploaded images are stored, are not correct. The web server has to be able to write to the images directory in order to move the "temporary" file created when a file is uploaded through a web interface to its permanent home in the images directory. Changing the permissions on the "images" directory so that the web server can write to the directory will alleviate the problem.

Checking the file, it seems that the user that uploads the file is: nobody
Can that be changed?

"Nobody" is the web user designated in the apache configuration file, and has nothing to do with your MediaWiki users. Every application in a Unix environment has to belong to a system user, whether that user is 'root' or another user. "Nobody" is a frequently used system-designatd user/group name in apache configuration files that designates the system "user" that Apaches runs under. It is Apache (and, as such, the Apache user) that is responsible for processing the file upload request, which is why you see that the uploaded file belongs to the system user "nobody".