Installing and Configuring the External Storage: Windows Network Drives App
- Enabling External Storage
- Creating a New Share
- Personal WND Mounts
- libsmbclient Issues
- Windows Network Drive Listener
- Setting Up the WND Listener
- Basic Setup for One ownCloud Server
- Password Options
- Optimizing wnd:process-queue
- The File Serializer
- Interaction Between Listener, Serializer, and Windows Password Lockout
- Multiple Server Setup
- Basic Command Execution Examples
The External Storage: Windows Network Drives app creates a control panel in your Admin page for seamlessly integrating Windows and Samba/CIFS shared network drives as external storages.
Any Windows file share and Samba servers on Linux and other Unix-type operating systems use the SMB/CIFS file-sharing protocol. The files and directories on the SMB/CIFS server will be visible on your Files page just like your other ownCloud files and folders.
They are labeled with a little four-pane Windows-style icon, and the left pane of your Files page includes a Windows Network Drive filter. Figure 1 shows a new Windows Network Drive share marked with red warnings.
These indicate that ownCloud cannot connect to the share because it requires the user to login, it is not available, or there is an error in the configuration.
|For more information on SMB/CIFS in ownCloud, refer to the Samba file server configuration documentation.|
Files are synchronized bi-directionally, and you can create, upload, and delete files and folders. ownCloud server admins can create Windows Network Drive mounts and optionally allow users to set up their own personal Windows Network Drive mounts.
Depending on the authentication method, passwords for each mount are
encrypted and stored in the ownCloud database, using a long random
secret key stored in
config.php, which allows ownCloud to access the
shares when the users who own the mounts are not logged in. Or,
passwords are not stored and available only for the current session,
which adds security.
Install the External Storage: Windows Network Drives app from the ownCloud Market App or ownCloud Marketplace. To make it work, a few dependencies have to be installed.
A Samba client. This is included in all Linux distributions. On Debian, Ubuntu, and other Debian derivatives it is called
smbclient. On SUSE, Red Hat, CentOS, and other Red Hat derivatives it is
php-smbclient(version 0.8.0+). It should be included in most Linux distributions. You can use eduardok/libsmbclient-php, if your distribution does not provide it.
stdbuf. These should be included in most Linux distributions.
Assuming that your ownCloud installation is on Ubuntu, then the following commands will install the required dependencies:
# Install core packages sudo apt-get update -y sudo apt-get install -y smbclient php-smbclient coreutils
Other method using PECL is:
# Install php-smbclient using PECL pecl install smbclient # Install it from source git clone git://github.com/eduardok/libsmbclient-php.git cd libsmbclient-php ; phpize ./configure make sudo make install
Regardless of the method you use, remember to check if an smbclient.ini
file exists in
If so, then make it available via by running the following command:
sudo phpenmod -v ALL smbclient
To enable external storage go to, as the ownCloud administrator. Tick the checkbox to enable external storage.
When you create a new WND share you need three things:
The login credentials for the share
The server address, the share name; and
The folder you want to connect to
Treat all the parameters as being case-sensitive.
Although some parts of the app might work properly, regardless of case, other parts might have problems if case isn’t respected.
Enter the ownCloud mount point for your new WND share. This must not be an existing folder.
Then select your authentication method; See enterprise_only_auth for complete information on the five available authentication methods.
Enter the address of the server that contains the WND share.
The Windows share name.
The root folder of the share. This is the folder name, or the
$uservariable for user’s home directories. Note that the LDAP
Internal Username Attributemust be set to the
samaccountnamefor either the share or the root to work, and the user’s home directory needs to match the
samaccountname. (See User Authentication with LDAP.)
Select users or groups with access to the share. The default is all users.
Click the gear icon for additional mount options. Note that previews are enabled by default, while sharing is not (see figure 2). Sharing is not available for all authorization methods; see enterprise_only_auth. For large storages with many files, you may want to disable previews, because this can significantly increase performance.
Your changes are saved automatically.
|When you create a new mountpoint using Login credentials, you must log out of ownCloud and then log back in so you can access the share. You only have to do this the first time.|
Users create their own WND mounts on their Personal pages. These are created the same way as Admin-created shares. Users have four options for login credentials:
Username and password
Log-in credentials, save in session
Log-in credentials, save in database
If your Linux distribution ships with
libsmbclient 3.x, which is
included in the Samba client, you may need to set up the HOME variable
in Apache to prevent a segmentation fault. If you have
libsmbclient 4.1.6 and higher it doesn’t seem to be an issue, so you
won’t have to change your HOME variable. To set up the HOME variable on
Ubuntu, modify the
unset HOME export HOME=/var/www
In Red Hat/CentOS, modify the
/etc/sysconfig/httpd file and add the
following line to set the HOME variable in Apache:
By default, CentOS has activated SELinux, and the
httpd process can
not make outgoing network connections. This will cause problems with the
samba libraries. You’ll need to get around this to
make this work. First, check the status:
getsebool -a | grep httpd httpd_can_network_connect --> off
Then enable support for network connections:
setsebool -P httpd_can_network_connect 1
In openSUSE, modify the
Restart Apache, open your ownCloud Admin page and start creating SMB/CIFS mounts.
The SMB protocol supports registering for notifications of file changes
on remote Windows SMB storage servers. Notifications are more efficient
than polling for changes, as polling requires scanning the whole SMB
storage. ownCloud supports SMB notifications with an
|The notifier only works with remote storage on Windows servers. It does not work reliably with Linux servers due to technical limitations.|
smbclient version needs to be 4.x, as older versions do not
support notifications. The ownCloud server needs to know about changes
to files on integrated storage so that the changed files will be synced
to the ownCloud server, and to desktop sync clients.
Files changed through the ownCloud Web Interface, or sync clients are automatically updated in the ownCloud file cache, but this is not possible when files are changed directly on remote SMB storage mounts.
To create a new SMB notification, start a listener on your ownCloud
occ wnd:listen. The listener marks changed files, and a
background job updates the file metadata.
Windows network drive connections and setup of
occ wnd:listen often
does not always work the first time. If you encounter issues using it,
then try the following troubleshooting steps:
Check the connection with smbclient on the command line of the ownCloud server
Take the example of attempting to connect to the share named MyData
occ wnd:listen. Running the following command would work:
sudo -u www-data ./occ wnd:listen MyHost MyData svc_owncloud password
However, running this command would not:
sudo -u www-data ./occ wnd:listen MyHost mydata svc_owncloud password
The WND listener for ownCloud 10 includes two different commands that need to be executed:
This command listens and stores notifications in the database coming from one specific host and share. It is intended to be run as a service. The command requires the host and share, which the listener will listen to, and the Windows/Samba account that will listen. The command does not produce any output by default, unless errors happen.
You can increase the command’s verbosity by using
The simplest way to start the
wnd:listen process manually, perhaps for
initial testing, is as follows
sudo -u www-data ./occ wnd:listen <host> <share> <username>
The password is an optional parameter and you’ll be asked for it if you
didn’t provide it, as in the example above. In order to start the
wnd:listen without any user interaction, provide the password as the
user’s 4th parameter, as in the following example:
sudo -u www-data ./occ wnd:listen <host> <share> <username> <password>
For additional options to provide the password, check Password Options
Note that in any case there won’t be any processing of the password by
default. This means that spaces or newline chars won’t be removed unless
explicitly told. Use the
--password-trim option in those cases.
You should be able to run any of those commands, and/or wrap them into a
systemd service or any other startup service, so that the
command is automatically started during boot, if you need it.
This command processes the stored notifications for a given host and
share. This process is intended to be run periodically as a Cron job, or
via a similar mechanism. The command will process the notifications
stored by the
wnd:listen process, showing only errors by default. If
you need more information, increase the verbosity by calling
As a simple example, you can check the following:
sudo -u www-data ./occ wnd:process-queue <host> <share>
You can run that command, even if there are no notifications to be processed.
As said, you can wrap that command in a Cron job so it’s run every 5 minutes for example.
First, go to the admin settings and set up the required WND mounts. Be aware though, that there are some limitations. These are:
We need access to the Windows account password for the mounts to update the file cache properly. This means that "login credentials, saved in session" won’t work with the listener. "login credentials, saved in DB" should work and could be the best replacement.
$userplaceholder in the share, such as
//host/$user/path/to/root, for providing a share which is accessible per/user won’t work with the listener. This is because the listener won’t scale, as you’ll need to setup one listener per/share. As a result, you’ll end up with too many listeners. An alternative is to provide a common share for the users and use the
$userplaceholder in the root, such as
Second, start the
wnd:listen process if it’s not already started,
ideally running it as a service. If it isn’t running, no notification
are stored. The listener stores the notifications. Any change in the
mount point configuration, such as adding or removing new mounts, and
logins by new users, won’t affect the behavior, so there is no need to
restart the listener in those cases.
In case you have several mount point configurations, note that each
listener attaches to one host and share. If there are several mount
configurations targeting different shares, you’ll need to spawn one
listener for each. For example, if you have one configuration with
10.0.0.2/share1 and another with
10.0.0.2/share2, you’ll need to
spawn 2 listeners, one for the first configuration and another for the
Third, run the
wnd:process-queue periodically, usually via
a Cron job <cron_job_label>. The command processes all the stored
notifications for a specific host and share. If you have several, you
could set up several Cron jobs, one for each host and share with
different intervals, depending on the load or update urgency. As a
simple example, you could run the command every 2 minutes for one server
and every 5 minutes for another.
As said, the command processes all the stored notifications, squeeze
them and scan the resulting folders. The process might crash if there
are too many notifications, or if it has too many storages to update.
--chunk-size option will help by making the command process all
the notifications in buckets of that size.
On the one hand the memory usage is reduced, on the other hand there is more network activity. We recommend using the option with a value high enough to process a large number of notifications, but not so large to crash the process. Between 200 and 500 should be fine, and we’ll likely process all the notifications in one go.
There are several ways to supply a password:
Interactively in response to a password prompt.
sudo -u www-data ./occ wnd:listen <host> <share> <username>
Sent as a parameter to the command.
sudo -u www-data ./occ wnd:listen <host> <share> <username> <password>
Read from a file, using the
--password-fileswitch to specify the file to read from. Note that the password must be in plain text inside the file, and neither spaces nor newline characters will be removed from the file by default, unless the
--pasword-trimoption is added. The password file must be readable by the apache user (or www-data)
sudo -u www-data ./occ wnd:listen <host> <share> <username> \ --password-file=/my/secret/password/file
sudo -u www-data ./occ wnd:listen <host> <share> <username> \ --password-file=/my/secret/password/file --password-trim
If you use the
Using 3rd party software to store and fetch the password. When using this option, the 3rd party app needs to show the password as plaintext on standard output.
cat /tmp/plainpass | sudo -u www-data ./occ wnd:listen <host> <share> <username> --password-file=-
This provides a bit more security because the
should be owned by root and only root should be able to read the file
(0400 permissions); Apache, particularly, shouldn’t be able to read it.
It’s expected that root will be the one to run this command.
base64 -d /tmp/encodedpass | sudo -u www-data \ ./occ wnd:listen <host> <share> <username> --password-file=-
Similar to the previous example, but this time the contents are encoded in Base64 format (there’s not much security, but it has additional obfuscation).
Third party password managers can also be integrated. The only requirement is that they have to provide the password in plain text somehow. If not, additional operations might be required to get the password as plain text and inject it in the listener.
As an example:
You can use "pass" as a password manager. You can go through http://xmodulo.com/manage-passwords-command-line-linux.html to setup the keyring for whoever will fetch the password (probably root) and then use something like the following
pass the-password-name | sudo -u www-data ./occ wnd:listen <host> <share> <username> --password-file=-
|Do not use this option if the process-queue is fast enough. The option has some drawbacks, specifically regarding password changes in the backend.|
wnd:process-queue creates all the storages that need to be updated
from scratch. To do so, we need to fetch all the users from all the
backends (currently only the ones that have logged in at least once
because the others won’t have the storages that we’ll need updates).
To optimize this,
wnd:process-queue make use of two switches:
–serializer-params. These serialize
storages for later use, so that future executions don’t need to fetch
the users, saving precious time — especially for large organizations.
While the specific behavior will depend on the serializer implementation, the overall behavior can be simplified as follows:
If the serializer’s data source (such as a file, a database table, or some Redis keys) has storage data, it uses that data to create the storages; otherwise, it creates the storages from scratch.
After the storages are created, notifications are processed for the storages. If the storages have been created from scratch, those storages are written in the data source so that they can be read on the next run.
|It’s imperative to periodically clean up the data source to fetch fresh data, such as for new storages and updated passwords. There isn’t a generic command to do this from ownCloud, because it depends on the specific serializer type. Though this option could be provided at some point if requested.|
The file serializer is a serializer implementation that can be used with
wnd:process-queue command. It requires an additional parameter
where you can specify the location of the file containing the serialized
There are several things you should know about this serializer:
The generated file contains the encrypted passwords for accessing the backend. This is necessary in order to avoid re-fetching the user information, when next accessing the storages.
The generated file is intended to be readable and writable only for the web server user. Other users shouldn’t have access to this file. Do not manually edit the file. You can remove the file if it contains obsolete information.
Only one file serializer should be used per server and share, as the serialized file has to be per server and share. Consider the following usage scenario:
If you have three shares:
10.0.10.20/share2, then you should use three different calls to
wnd:process-queue, changing the target file for the serializer for each one.
Since the serialized file has to be per server and share, the serialized file has some checks to prevent misuse. Specifically, if we detect you’re trying to read the storages for another server and share from the file, the contents of the file won’t be read and will fallback to creating the storage from scratch. At this point, we’ll then update the contents of that file with the new storage.
Doing so, though, creates unneeded competition, where several process-queue will compete for the serializer file. For example, let’s say that you have two process-queues targeting the same serializer file. After the first process creates the file the second process will notice that the file is no longer available. As a result, it will recreate the file with new content.
At this point the first process runs again and notices that the file isn’t available and recreate the file again. When this happens, the serializer file’s purpose isn’t fulfilled As a result, we recommend the use of a different file per server and share.
Windows supports password lockout policies. If one is enabled on the server where an ownCloud share is located, and a user fails to enter their password correctly several times, they may be locked out and unable to access the share.
This is a known issue
that prevents these two inter-operating correctly.
Currently, the only viable solution is to ignore that feature and use
wnd:process-queue, without the serializer
There is also an additional issue to take into account though, which is
that parallel runs of
wnd:process-queue might lead to a user lockout.
The reason for this is that several
wnd:process-queue might use the
same wrong password because it hasn’t been updated by the time they
As a result, it’s recommended to force the execution serialization of that command to prevent this issue. You might want to use Anacron, which seems to have an option for this scenario, or wrap the command with flock.
If you need to serialize the execution of the
the following example with
flock -n /my/lock/file sudo -u www-data ./occ wnd:process-queue <host> <share>
In that case, flock will try get the lock of that file and won’t run the
command if it isn’t possible. For our case, and considering that file
isn’t being used by any other process, it will run only one
wnd:process-queue at a time. If someone tries to run the same command
a second time while the previous one is running, the second will fail
and won’t be executed. Check flock’s documentation
for details and other options.
Setups with several servers might have some difficulties in some scenarios:
wnd:listencomponent might be duplicated among several servers. This shouldn’t cause a problem, depending on the limitations of the underlying database engine. The supported database engines should be able to handle concurrent access and de-duplication.
wnd:process-queueshould also be able to run from any server, however limitations for concurrent executions still apply. As a result, you might need to serialized command execution of the
wnd:process-queueamong the servers (to avoid for the password lockout), which might not be possible or difficult to achieve. You might want to execute the command from just one specific server in this case.
wnd:process-queue+ serializer. First, check the above section to know the interactions with the password lockout. Right now, the only option you have to set it up is to store the target file in a common location for all the server. We might need to provide a specific serializer for this scenario (based on Redis or DB)
sudo -u www-data ./occ `wnd:listen` host share username password sudo -u www-data ./occ `wnd:process-queue` host share sudo -u www-data ./occ `wnd:process-queue` host share -c 500 sudo -u www-data ./occ `wnd:process-queue` host share -c 500 \ --serializer-type file \ --serializer-params file=/opt/oc/store sudo -u www-data ./occ `wnd:process-queue` host2 share2 -c 500 \ --serializer-type File \ --serializer-params file=/opt/oc/store2
To set it up, make sure the listener is running as a system service:
sudo -u www-data ./occ `wnd:listen` host share username password
Setup a Cron job or similar with something like the following two commands:
sudo -u www-data ./occ wnd:process-queue host share -c 500 \ --serializer-type file \ --serializer-params file=/opt/oc/store1 rm -f /opt/oc/store1 # With a different schedule
The first run will create the
/opt/oc/store1 with the serialized
storages, the rest of the executions will use that file. The second Cron
job, the one removing the file, will force the
refresh the data.
It’s intended to be run in a different schedule, so there are several
executions of the
wnd:process-queue fetching the data from the file.
Note that the file can be removed manually at any time if it’s needed
(for example, the admin has reset some passwords, or has been notified
about password changing).