in /etc/redis.conf
#unixsocket /tmp/redis.sock
unixsocket /run/redis/redis.sock
unixsocketperm 777
in der nextcloud config: /usr/share/nginx/nextcloud/config/config.php
'memcache.locking' => '\OC\Memcache\Redis',
'redis' =>
array (
'host' => '/run/redis/redis.sock',
'port' => 0,
'timeout' => 0.0,
),