HP EVA Updating Product Software Guide (xcs10001000) (5697-2423, December 2012)

5. To review update recommendations for your switches and HBAs, select the applicable folder
on the left side of the window. In Figure 5 (page 18), it is the folder called MySwitchGroup.
Look for the group name you created in step 2 of “Using SAN Visibility” (page 12).
The Best Practices and Recommendations window opens (Figure 6 (page 19)).
Figure 6 Sample SAN Recommendations
If the firmware or driver version recommended is later than what is currently running, ensure
that you upgrade the appropriate switch or HBA.
NOTE: After completing required upgrades, HP recommends that you create a new SAN Visibility
report to verify that all upgrades were successful.
Evaluating your configuration
Consider the following factors when determining if an online upgrade is appropriate for your
environment:
• Queuing host I/O—After the upgrade, the array performs a resynchronization. During the
resynchronization, host I/O is queued to the host, which can create a backlog of requests for
processing when the array is able to respond. The resynchronization may take less than a
minute, but it may take time to clear the backlog of requests and some host I/O may experience
timeouts. The HP recommended driver timeout value is 60 seconds. When an I/O timeout
occurs, multipath drivers typically retry the I/O request on the same or an alternate path.
These retry algorithms have operating system and HBA dependencies and may extend the
time that host I/O will be allowed to complete successfully beyond the 60–second timeout.
Additionally, some applications may be more sensitive to I/O delays.
• Processing host I/O during the upgrade—The upgrade competes with host requests that have
a higher priority, which can affect the upgrade outcome. To ensure that host I/O from business
Evaluating your configuration 19