An engineer adds a new FlexCache volume but clients occasionally are redirected to the origin volume for reads. What is the most likely cause?

An engineer adds a new FlexCache volume but clients occasionally are redirected to the origin volume for reads. What is the most likely cause?

• A. The origin volume has been de-peered, forcing all traffic to redirect.
• B. The requested blocks were not yet cached in the FlexCache volume.
• C. ONTAP FlexCache volumes cannot directly serve read requests.
• D. The FlexCache volume is operating in write-back mode.

Answer: (B)

FlexCache serves reads from the cache first, and if the requested data isn’t already in the cache, it fetches it from the origin and then caches it for future requests. Seeing reads occasionally go to the origin means those particular blocks haven’t been cached yet (cache misses). Once those blocks are requested and brought into the FlexCache, subsequent reads for them will be served locally from the cache, reducing redirection to the origin. The other possibilities don’t fit as well: de-peering would affect traffic more broadly and isn’t indicated by occasional redirections; FlexCache can serve reads directly; and write-back mode affects how writes are cached, not the read path.

FlexCache serves reads from the cache first, and if the requested data isn’t already in the cache, it fetches it from the origin and then caches it for future requests. Seeing reads occasionally go to the origin means those particular blocks haven’t been cached yet (cache misses). Once those blocks are requested and brought into the FlexCache, subsequent reads for them will be served locally from the cache, reducing redirection to the origin.

The other possibilities don’t fit as well: de-peering would affect traffic more broadly and isn’t indicated by occasional redirections; FlexCache can serve reads directly; and write-back mode affects how writes are cached, not the read path.