ONTAP Discussions

Any Situation to Read Data from a DP Volume?


Greeting everyone.


My question originates from a description mentioned in FabricPool feature,



On Page 8, "If read, cold data blocks on the cloud tier become hot and are written to the performance tier. "

This description is to describe read behavior of a cold block from a volume with Backup tiering policy.


In normal situation, the Backup tiering policy can only be applied to DP volume, which could not have a junction path so no client can read from a DP volume. For non-DP volume, we can designate the Backup tiering-policy while performing a volume move, but it will revert to the Auto tiering-policy as it finishes, so technically we do not read from a volume with the Backup tiering policy. If we perform a flexclone from the DP volume and read from the flexclone volume, it is no longer with the Backup tiering policy and we do not read from a volume with the Backup tiering policy again.


Hence here comes the question, on what condition can we read data from a volume with the Backup tiering policy? To the best of my knowledge, SnapMirror cascades can be a possible situation, where the data in the secondary DP volume would be read and transfer to the tertiary DP volume. Is there any possibility to have another situation other than that?


Any reply would be very much appreciated.






You might be looking at Flexcache. SnapMirror is specifically for DR/backup site type situations. It's not meant for remote data volumes. That was introduced in 9.5.


Maybe can you explain your need better?


Also this is an architecting question so the account team may be able to provide feedback or help work a solution for your needs.