Spark persist temp view

I'm trying to persist a temp view with the purpose of querying it again via sql:

val df = spark.sqlContext.read.option("header", true).csv("xxx.csv")
df.createOrReplaceTempView("xxx")

persist/cache:

df.cache()                          // or
spark.sqlContext.cacheTable("xxx")  // or
df.persist(MEMORY_AND_DISK)         // or
spark.sql("CACHE TABLE xxx")

Then I move the underlying xxx.csv, and:

spark.sql("select * from xxx")

Upon which, I find that only CACHE TABLE xxx stores a copy. What am I doing wrong, how can persist eg. DISK_ONLY a queryable view/table?