Can't generate thumbs, LAMP installation on DigitalOcean

I run Kirby on my DigitalOcean LAMP setup and have trouble with the thumb function. It doesn’t generate any thumbs at all. If I do:

<img src="<?php echo thumb($image, array('width' => 272, 'quality' => 90), false) ?>" />

I just get the original image url. I tried the default GD drive and also tried to install ImageMagick and switch the drive to:

c::set('thumbs.driver', 'im');
thumb::$defaults['bin'] = '/usr/bin/convert';

But still no luck. I want to use ImageMagic in the end, but doesn’t understand why the default GD drive doesn’t work either.

Look for a directory “/thumbs”.

Does it exist and can the webserver write files in this directory?

Some times it’s just to simple…
The folder was there but wasn’t writeable for the server… it had the rights 755 which I thought was ok. Now when I tried to set it to 777 it worked. But that doesn’t feel right. Tried 775 but didn’t work. How about security?

… depends on the installation, which I never used.

Ask your hoster or wait for hints here…

The rights should be set to 755, not 777. I wonder if it’s a problem of ownership, see last post in this thread: Kirby on DigitalOcean LAMP URLS doesn’t work

Yes, instead of widening the permissions, please change the owner of the folder:

chown www-data:www-data thumbs

Thank you all for the help.
I think I need to setup my server a little bit different so I don’t use the root user. I will follow this guide: