Our organization is planning to deploy FabricPool, and we are doing some testing prior to rollout. We want to see how it behaves, what caveats there may be, and how it performs.
We have StorageGRID as our S3 target, and OnTAP 9.8 on FAS. We have successfully setup FabricPool and have a set of test volumes. Some have their tiering-policy set to auto and some to snapshot-only. We have confirmed (using 'volume show-footprint') that most of the data on the volumes has been sent to the object store.
One of our tests asks the question, "what happens if communications between OnTAP and SG are lost or interrupted?" To simulate a failure, we have removed the SG HA Group (the Virtual IP) which OnTAP uses to talk to the S3 bucket. As expected, OnTAP throws error events and labels the object-store as 'unavailable'.
Now, my assumption is that if I attempt to access snapshots or files on my tiered volume, I should get a failure or error. But I have not been able to make it fail.
Example- one volume has snapshot-only tiering policy, and it appears from the volume footprint that all the snaps have been sent to the capacity tier. But I can copy data out of a number of snapshots just fine even though the SG is effectively off the network.
Similarly, for the volume with the 'auto' policy, nearly 100% of the data blocks (396Gb of a 400Gb volume) are on the capacity tier, yet I can read at least 20Gb of data from the volume.
Not a major issue, but it is confusing that I can still read data blocks which were allegedly removed from the performance tier.
Any hints on how FabricPool rally works under the covers?