Login into the Nexcloud webpage.

At the left, there is an account menu where you can choose the administrator page. On that page there is an update button that starts the update. Its quite easy. It starts to check for write permissions. if these fail, there is something wrong with the permissions of your nextcloud database. Simply repair that with this command:

sudo chown -R www-data:www-data /var/www/nextcloud 

or whatever directory gives the permission error. I moved my nextcloud to /var/www/html/nextcloud so I had to enter that.

You can simplky read the permission errors to know the correct path.

When the  permissions are right, everything should go straight forward.

After updateing from 11.0.2 to 11.0.3 i got an error and couldnt restart te update proces. I had to SSH into the raspberry and give these commands:

cd /var/www/html/nextcloud

sudo -u www-data ./occ upgrade

and the update process was finished within several minutes. After that, you could finish the update job from the web login.

Read more about that here:

Source webpage:   https://docs.nextcloud.com/server/9/admin_manual/maintenance/manual_upgrade.html

Always start by making a fresh backup and disabling all 3rd party apps.

Put your server in maintenance mode. This prevents new logins, locks the sessions of logged-in users, and displays a status screen so users know what is happening. There are two ways to do this, and the preferred method is to use theocc command, which you must run as your HTTP user. This example is for Ubuntu Linux:

sudo -u www-data php occ maintenance:mode --on

The other way is by entering your config.php file and changing 'maintenance' => false, to 'maintenance' =>true,.

1. 1.Back up your existing Nextcloud Server database, data directory, and config.php file. (See Backing up Nextcloud.) 

2. 2.Download and unpack the latest Nextcloud Server release (Archive file) from nextcloud.com/install/ into an empty directory outside of your current installation. 

   Note 

   To unpack your new tarball, run: tar xjf nextcloud-[version].tar.bz2 

3. 3.Stop your Web server. 

4. 4.Rename your current Nextcloud directory, for example nextcloud-old. 

5. 5.Unpacking the new archive creates a new nextcloud directory populated with your new server files. Copy this directory and its contents to the original location of your old server, for example /var/www/, so that once again you have /var/www/nextcloud. 

6. 6.Copy the config.php file from your old Nextcloud directory to your new Nextcloud directory. 

7. 7.If you keep your data/ directory in your nextcloud/ directory, copy it from your old version of Nextcloud to your new nextcloud/. If you keep it outside of nextcloud/ then you don’t have to do anything with it, because its location is configured in your original config.php, and none of the upgrade steps touch it. 

8. 8.If you are using 3rd party applications, look in your new nextcloud/apps/ directory to see if they are there. If not, copy them from your old apps/ directory to your new one. Make sure the directory permissions of your third party application directories are the same as for the other ones. 

9. 9.Restart your Web server. 

10. 10.Now launch the upgrade from the command line using occ, like this example on CentOS Linux: 

    sudo -u apache php occ upgrade 

11. 11.The upgrade operation takes a few minutes to a few hours, depending on the size of your installation. When it is finished you will see a success message, or an error message that will tell where it went wrong. 

Assuming your upgrade succeeded, disable the maintenance mode:

sudo -u www-data php occ maintenance:mode --off

Login and take a look at the bottom of your Admin page to verify the version number. Check your other settings to make sure they’re correct. Go to the Apps page and review the core apps to make sure the right ones are enabled. Re-enable your third-party apps. Then apply strong permissions to your Nextcloud directories (Setting Strong Directory Permissions).

Previous Nextcloud Releases

You’ll find previous Nextcloud releases in the Nextcloud Server Changelog.

Reverse Upgrade

If you need to reverse your upgrade, see Restoring Nextcloud.

Troubleshooting

When upgrading Nextcloud and you are running MySQL or MariaDB with binary logging enabled, your upgrade may fail with these errors in your MySQL/MariaDB log:

An unhandled exception has been thrown:

exception 'PDOException' with message 'SQLSTATE[HY000]: General error: 1665

Cannot execute statement: impossible to write to binary log since

BINLOG_FORMAT = STATEMENT and at least one table uses a storage engine limited

to row-based logging. InnoDB is limited to row-logging when transaction

isolation level is READ COMMITTED or READ UNCOMMITTED.'

Please refer to MySQL / MariaDB with Binary Logging Enabled on how to correctly configure your environment.

Occasionally, files do not show up after a upgrade. A rescan of the files can help:

sudo -u www-data php console.php files:scan --all

See the nextcloud.com support page for further resources.

Sometimes, Nextcloud can get stuck in a upgrade. This is usually due to the process taking too long and encountering a PHP time-out. Stop the upgrade process this way:

sudo -u www-data php occ maintenance:mode --off

Then start the manual process:

sudo -u www-data php occ upgrade

If this does not work properly, try the repair function:

sudo -u www-data php occ maintenance:repair