Considerations for session-oriented protocols
Clusters and session-oriented protocols might cause adverse effects on clients and applications in certain areas such as I/O service during upgrades.
If you are using session-oriented protocols, consider the following:
-
SMB
If you serve continuously available (CA) shares with SMBv3, you can use the automated nondisruptive upgrade method (with System Manager or the CLI), and no disruption is experienced by the client.
If you are serving shares with SMBv1 or SMBv2, or non-CA shares with SMBv3, client sessions are disrupted during upgrade takeover and reboot operations. You should direct users to end their sessions before you upgrade.
Hyper-V and SQL Server over SMB support nondisruptive operations (NDOs). If you configured a Hyper-V or SQL Server over SMB solution, the application servers and the contained virtual machines or databases remain online and provide continuous availability during the ONTAP upgrade.
-
NFSv4.x
NFSv4.x clients will automatically recover from connection losses experienced during the upgrade using normal NFSv4.x recovery procedures. Applications might experience a temporary I/O delay during this process.
-
NDMP
State is lost and the client user must retry the operation.
-
Backups and restores
State is lost and the client user must retry the operation.
Do not initiate a backup or restore during or immediately before an upgrade. Doing so might result in data loss. -
Applications (for example, Oracle or Exchange)
Effects depend on the applications. For timeout-based applications, you might be able to change the timeout setting to longer than the ONTAP reboot time to minimize adverse effects.