FAST VP VMAX 10K new LUN is always slow

I can think of a few things that may be impacting the performance with a new LUN vs. an older LUN.

1st is cache.  It may take time for cache to get populated and to get higher read hit rates.

2nd is FAST.  It takes time for FAST to promote extents based on workload.  Where are you binding these new LUNs?

3rd is allocation overhead.  Until all the extents are all written they will have slightly higher response times.

What tier are the new devices bound to?

Thank you so much Quincy56 for the answers. Our system seems ok now after 2 days. That's a bit slow, but finally it is ok.

To which disk technology the LUN is bounded, FC, SATA , etc ?

I am sorry but I don't get you of the tier. It is in the same storage box as the old one if that's what you mean.

Thats might be the reason and I am sure now the extents wont be in SATA tier

Oh ok, sorry. it is on sata.

Sorry, i am quite new on this one, but we actually use FC and EFD with EFD larger than FC.

Thanks.

There are some consideration prior LUN allocation, please check them before you proceed.
For achieving better performance

Will do.

Thanks.

There was a feature added to FAST VP called allocation by policy.  Prior to that feature if the bound pool ran out of space, allocations would fail.  With the feature, new allocations can occur in any tier that is in the FAST VP policy.  Because of this, the old recommendation was to bind devices to the pool with the most capacity, usually SATA.  With this newer feature, we do NOT recommend binding to SATA ever.  Bind to the middle tier if you have 3, or to the highest tier, if there are only two tiers in the FAST VP policy.

Binding to SATA will ensure that you get slow performance for initial allocations.

Thank you Quincy. However I come to realise that we are actually using FC and EFD. Our system is doing fine with the normal speed now.