HP StorageWorks Enterprise Virtual Array Online Firmware Upgrade Best Practices (5697-6388, January 2007)

Figure 20 shows I/Os per second for both reads and writes. During normal operation, there is roughly a
60-40 split between reads a nd writes on the port in question. During the firmware upgrade, the number of
I/Os per second drops to nearly zero as the EVA 4000 handles the firmware upgrade. They do, however,
return to a steady state once the upgrade is completed. Figure 21 shows a co m bined view of all I/Os per
second across the entire array, also displaying the same sharp drop in performance during the upgrade.
Figure
20 Heavy load on EVA, I/Os per second
40
Effect of online firmware upgrade on application resiliency