Plan the upgrade
Upgrade readiness considerations
At this time, there is no back out plan from an upgrade. Once you start the upgrade process, you must finish it. Before you start the upgrade, consider the following:
- When you upload a new upgrade file onto your system, it replaces the previously uploaded version. There can only be one upgrade candidate on the system at a time.
- You will be prevented from using Unisphere or the CLI to make configuration changes to the system while the upgrade is in progress.
- Unisphere may be temporarily disconnected during the upgrade. Access to Unisphere is automatically re-established after the upgrade completes.
- EMC strongly suggests you perform a system health check about a week before installing an upgrade, to ensure that you have time to resolve underlying problems that may prevent a successful update.
- Attempt to reduce the I/O to the system during the upgrade process as much as possible. While the upgrade is non-disruptive, there is only one storage processor handling I/O, so performance will be reduced.
- Any hot fixes installed prior to the upgrades are automatically removed during the upgrade. If the hot fix is not included in the upgrade, ensure that you install the hot fix again after the upgrade. Refer to the relevant Release Notes to ensure that the issue addressed by the hot fix is included as a fixed issue in the new system OE software version.
Common issues that can interrupt an upgrade
The following common issues may interrupt an upgrade:
- Faulted component
If a component has faulted, an alert may already be present in Unisphere. You can also check for any faulted components in the System View page of Unisphere. Once you identify the component, make the necessary replacements, and then try running the upgrade again.
Before you start the upgrade process, it is recommended that you perform a pre-upgrade health check. It checks for any hardware faults and the health of the file system. Ensure that there are no issues reported.
- Incompatible software update file
Some software upgrades require that you are running on a specific version. Refer to the Release Notes document associated with the software update. For more information, see Information on changes and new features in a release.
- Corrupt software update file
Use the MD5 checksum method to confirm whether the software update file is corrupt. For more information, see Verify that the upgrade file is not corrupted.
If the file is corrupted, download the software update one more time, verify it using MD5 checksum, and then proceed with the upgrade.
It is recommended that you always verify that the software update file is valid and not corrupt using the MD5 checksum.
- Large and complex configurations
The pre-upgrade health check may fail if the system exceeds the total number of allowed file systems and snapshots. Refer to the Unisphere Online Help for more information on such limitations.
When this occurs, the system will recommend that users delete some of the snapshots to enable the upgrade.
Time needed to complete an upgrade
The total estimated time for an upgrade is around 1 hour and 15 minutes. It may change based on the I/O activities and other factors specific to your environment. Do not take actions, such as closing and opening the Web browser or power cycling the SPs in the middle of an upgrade.
The upgrade retains your existing configuration settings. This includes the IP addresses you configured for the system (static or dynamic).
I/O activities during an upgrade
Unisphere may be temporarily disconnected during the upgrade. Once the upgrade is complete, it will automatically be reconnected. It is recommended that you reduce all I/O activity before you proceed with the upgrade.