Drupal - Got error 28 from storage engine query

So I had one site with suddenly error 28.

Warning: Got error 28 from storage engine query: SELECT DISTINCT b.* FROM blocks b LEFT JOIN blocks_roles r ON b.module = r.module AND b.delta = r.delta LEFT JOIN i18n_blocks i18n ON (b.module = i18n.module AND b.delta = i18n.delta) WHERE (i18n.language ='nl' OR i18n.language ='' OR i18n.language IS NULL) AND ( b.theme = 'seven' AND b.status = 1 AND (r.rid IN (2,4) OR r.rid IS NULL) )ORDER BY b.region, b.weight, b.module in /var/hosting/sobibor/longshadowofsobibor.com/includes/database.mysql.inc on line 148

As of the site contents I usually first suspect a hacker with extreme right wing sympathies to have destroyed part of the site.
But the issue was very simple and unbiased: Not enough diskspace!

Right wing disk thrower