Edit:

Just kidding this is not true at all, disregard the below post

GKE and Redis

Redis allows users to save data to a single file with the bgsave command. If left unspecified inside your redis.conf file, bgsave will write this data to /docker/host/dir:/data.

I had always assumed you needed to specifically mount a volume for this to work, however it apparently works even when no volume is specified, thus allowing easier deployment scaling in kubernetes.