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

Test results

Light load testing

Light load testing revealed that all three applications reported no errors of any kind during the ﬁrmware

upgrade, while displaying moderate to s igniﬁcant latency for the duration of the ﬁrmware upgrade. The

ﬁrmware upgrade lasted approximately six minutes, during which all three applications continued to

respondanddidnotcauseanyerrors.

While the ﬁrmware event did cause latencies that are unacc eptable for normal operation, the amount

of time the unacceptable values persisted is signiﬁcantly less than the amo unt of time that a system

shutdown, ﬁrmware upgrade and system restart would take.

Microsoft Exchange 20 03 per formed adequately until the ﬁrmware upgrade. See Figure 10.Thelarge

spike in LoadSim latency corresponds to the ﬁrmware upgrade. Once the upgrade was complete, the

Exchange system returned to normal operation with an acceptable latency (95th percentile Loadsim score

of < 1000). The average seconds per disk write mirrors the latency spike in the LoadSim score, but also

returns to a normal level after the event completes.

gure 10 Light load on Exch ange 2003

Effect of online ﬁrmware upgrade on application resiliency