PowerMax and VMAX All Flash Solutions Design (SRDF/A Design Considerations)

Question 1

What are the design factors in SRDF/A?

Answer 1

workload (throughput/block size, locality, peak time)

RPO

network distance (available bandwidth, compression)

Question 2

What are we sizing in SRDF/A?

Answer 2

cache

bandwidth

number of RAs

cycle time/RPO

DSE

Question 3

What must be balanced when designing SRDF/A?

Answer 3

bandwidth and cache

on average the writes coming into the system must be equal to the writes going out

Question 4

How do you configure bandwidth and cache for SRDF/A?

Answer 4

need to configure enough bandwidth so the average throughput is enough to drain all writes

without this no amount of cache helps

Question 5

Why does SRDF/A builds require additional cache?

Answer 5

to support peak production workloads and maintain replication

Question 6

What is peak time?

Answer 6

defines the timeline on which this average of the peak intervals must be calculated

used to evaluate the busiest time period of the workload

Question 7

What does peak time affect?

Answer 7

average write peak affects the link bandwidth and amount of cache required for buffering writes

Question 8

What does increasing peak time do?

Answer 8

decreases the SRDF link bandwidth requirement since it’s averaging over longer period of time

increases cache required since more data will be buffered

Question 9

What is necessary to size cache for SRDF/A?

Answer 9

highest Peak IO and duration

Question 10

What is the throughput requirement for SRDF/A?

Answer 10

link bandwidth must sustain the average peak write throughput of the environment