Getting Started; Upgrade Overview; Evaluate Your Configuration - HP 6400/8400 Software Manual

1 Getting started

This chapter provides information about required kits and reference documentation. Check that you
have met the requirements and have all the required materials before you begin the upgrade procedures
described in this guide.
HP Command View EVA can be implemented in two ways:
• Server-based management — HP Command View EVA is installed on a management server con-
nected to the EVA, providing management of multiple HP EVA storage systems. All components
of the software suite (HP Command View EVA, HP Command View EVAPerf, HP Storage System
Scripting Utility, SMI-S EVA) are installed. Server-based management applies to all EVA models.
• Array-based management — Beginning with HP Command View EVA 8.1, the EVA4400 is
shipped with HP Command View EVA pre-installed on the management module within the controller
enclosure. Only one component of the software suite (HP Command View EVA) is installed. Array-
based management applies only to the EVA4400.

Upgrade overview

Depending on the upgrade path for your configuration, an upgrade can be done either online or
offline.
• During an online upgrade, EVA controller software is upgraded while the controllers are receiving
I/O; the controllers resynchronize simultaneously, and both hosts and applications continue to
run. The resynchronization during an online upgrade represents a single disruption of I/O, not
the multiple disruptions seen with some upgrade types. However, you must consider host and ap-
plication timeouts when doing an online upgrade.
• During an offline upgrade (shutdown upgrade), all host I/O to the storage system must be stopped.
All applications and hosts are shut down before the controller upgrade is done, and restarted
when the upgrade is complete.
An offline upgrade requires scheduling time with application managers, and having staff on hand
to shut down and restart applications and hosts. While actual upgrade time may be short, offline
upgrades can require several hours to complete from the start of the first application shutdown
until all hosts and applications have returned to service.

Evaluate your configuration

The following factors can affect the success of an online upgrade. Consider these 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 resyn-
chronization, 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 the
backlog of requests may take time to clear and some host I/O may experience timeouts. The HP
recommended driver timeout values are 60 seconds. When an I/O timeout occurs, multipath
drivers will typically retry the I/O request on the same path or an alternate path. There are oper-
ating system and HBA dependencies on these algorithms. The retry algorithms may extend the
HP StorageWorks Enterprise Virtual Array updating product software guide (XCS 09522000) 9