Category Archives: Linux

Troubleshooting Apache-based Web Servers


If the directory files is not "owned" by the Web server there are two ways to proceed. These instructions assume you have shell access to the Web server. If you do not have shell access, please contact your hosting provider for additional support.

Ideally you will be able to change the "owner" of the directory files to match the name of the Web server. On a Unix or Linux-based server you may verify "who" the Web server is running as by issuing the following commands:

$ ps aux  |grep apache # for Apache 2.x
$ ps aux  |grep httpd # for Apache 1.x

Depending on your Web server one of these commands will return a series of lines like this:

www-data 13612  0.1  0.9  50640 20340 ? S 12:29   0:08 /usr/sbin/apache2 -k start

The first column in the returned text is the "user" that your Web server is operating as. In this case the user is www-data. To make your files directory writeable by the Web server you need to reassign its ownership using the following command:

$ chown -R www-data sites/default/files
$ chmod -R 0700 sites/default/files

If you do not have sufficient permissions on your server to change the ownership of the folder, the next best option is to provide group-write access to the folder with the following command:

$ chmod -R 0770 sites/default/files

You should also be able to adjust the directory’s permissions using an FTP program as outlined above.

Once you’ve completed these steps confirm the appropriate permissions have been assigned by navigating to Administer -> Reports -> Status report. Scroll to the section labelled, "File system" and confirm your settings are now correct.


The most dangerous and least secure option is to assign write access to "everyone." This option should be avoided at all costs. If the steps outlined above do not work, please consider adjusting your hosting configuration (e.g. add your Web server to the appropriate group) instead of granting write access to "everyone."

Unix and FileZilla file permissions

We programmers assume you users know all about this. If you don’t, here’s the upshot.

Every user (human, etc) has an account on the computer. If it’s a different computer, your account on it might be very different. In fact some programs like MySQL and Drupal have their own unattached user/permissions system where your username and password can be completely different. This section is about your Unix computer account, which you used to connect and mess around with your files on your Unix server.

The computer also has groups of users, like maybe the other people in your department or your classroom or platoon or rank. This way, they can give, or take away, permissions to a whole group of people at once.

Now there’s three users that are important: you, the web server, and everybody else. Usually the web server’s account name is www or _www or nobody or daemon or apache. Everything that Drupal and PHP do, they do as this user. Usually no actual person logs in as www, it’s reserved for the server, and magic makes the server assume the www user identity. Even if Atilla the Hun comes surfing to your web server, what he does, he does as www as far as the files are concerned.

So you have to make sure that each of you can do what you need to do:
– you should probably be able to read and write the files in the website you’re making
– www (drupal) needs to be able to read all the files, and needs to be able to write inside the files directory.
– everybody else probably should not be allowed any access at all.

Each file, and each directory (folder), has permissions on it telling who can mess with it, and how:

r means Read permission, you can see what’s inside. For a directory, it means you can see what files are inside. You might not have permission to do anything with those files, but at least you can see their names, and see what permissions you have with them.

w means Write permission, you can change the data in it. For a directory, it means you can add and remove and rename files in it. If you can’t delete a file, it’s not cuz you can’t write the file, it’s cuz you can’t write its directory.

x means Execute permission. For a directory, that means you can use it to get at files inside. Even if you don’t have read permission! If you know the name of the file, and you have x permission, you can use that file or directory (and directories beneath, if any).

Each file remembers three kinds of people who can mess with it:
– the User is one particular user, usually whoever created it, the ‘owner’.
– the Group is some group, oh, you can often change this if you’re the User. (If you are both the User and the Group, you only get the User permissions.)
– the Other is the rest of all the users, excluding the User and the Group.
This isn’t always convenient; sometimes you want only three different users to access it, or two groups, or whatever, but this is the way it’s worked since before 1980. Usually, you can figure out a way to make it work for you and the server.

OK so if you see permissions like this:
rwx rwx rwx nancy staff
that means that the User named Nancy can read & write & execute it, and so can the Group named Staff, and so can everybody else.

This however:
rwx — — nancy staff
means that Nancy can do everything, but nobody else can. Very private. And this:
rw- r– — nancy staff
means that Nancy can read and write, the staff can just read and everybody else is locked out. Programmers often abbreviate this into 3 digits where:
r = 4
w = 2
x = 1
and you add them to get a single digit, so rw- r– — turns into: 640. Compact but confusing if you’re not used to it. You’ll see these commonly:
rw = 6 (common on files you can change)
rx = 5 (common on directories you can’t change)
rwx = 7 (common on directories you can do anything with)

So probably you’ll need some situation where you and the server can get at what you have to get at, and everybody else is locked out. Remember that you can lock people out by simply removing x permission from a directory at the top – you don’t have to change every file.