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

Figure 22 shows the total Kilobytes per second b eing handled by the array. During the firmware upgrade,
the amount of data b eing handled by the array drops to a mere fraction of what it is capable of during
the normal course of operation. When the firmware upgrade is complete, however, the level of data
being processed returns to normal. Note that the upgrade event lasts approximately 6 minutes.
Figure 22 Heavy load on EVA, total KB/s
Conclusion
Two main conclusions can be reached from the data collected by this testing. The first is that the
applications tested have sufficientresiliencytoreportnoerrorsduringanormalEVAfirmware upgrade,
even du ring load. The programs did n ot fail during the upgrade event and returned to a steady state
immediately af ter the event was completed. No ramp time was required.
The second conclusion is that there is a d efinite performance impact to conducting an EVA firmware
upgrade during the operation of all three of these applications. The upgrade event i tself took between
six and ten minutes to complete. During that time, all three applications showed a significant decrease
in performance.
From this we can conclude that while the upgrade should complete successfully in the tested environment,
the performance impact would be unacceptable during peak business hours and would cause a poor
user experience.
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Effect of online firmware upgrade on application resiliency