Replication and auto-tiering

[NightBird]

I just have a little question,

What about impact of replication on auto-tiering array ? Do the replication via VMware CBT impact tiers level choice ?

Thx

[Gostev]

I am sure this would depend on the specific array and the logic the array's vendor uses for tiering... you should check with the specific vendor what kind of workloads trigger tier changes.

[NightBird]

EMC VNX (5200).

Do you have some feedback on this kind of system (VNX) ?

[dellock6]

I remember there are some VNX users in these forums, just wait and see if someone wants to jump in.
Generally speaking, maybe the I/O produced by Veeam is going to change the calculations made by the tiering algorytm, but "how" it's going to react is up to the given storage array. As an example, on other storage system where tiering is scheduled, we usually configure it to be executed outside of the veeam operations timeframe.
But this is imho more about not stressing even more the storage, because about the moving of hot blocks from low to high tier, I would say a Veeam backup is not going to change the "score" of a block, since it's only read once per job. If an algorythm is going to move a block up in a tier only after one read, it's not such an optimized algorythm if you ask me.
On the other side, if you are going to read a block that is already inside the high tier, well you're simply getting it faster...

Luca.