Supported SMB versions and functionality
Server Message Block (SMB) is a remote file-sharing protocol used by Microsoft Windows clients and servers. In ONTAP 9, all SMB versions are supported; however, SMB 1.0 support is disabled by default in Lenovo Data ONTAP. You should verify that the ONTAP SMB server supports the clients and functionality required in your environment.
SMB 2.0 and later versions are enabled by default for ONTAP 9 SMB servers, and can be enabled or disabled as needed.
SMB 1.0 is disabled by default but can be manually enabled by the user.
For environments with existing CIFS servers running SMB 1.0, you should migrate to a later SMB version as soon as possible to prepare for security and compliance enhancements. Contact your Lenovo representative for details.
The following table shows which SMB features are supported in each SMB version. Some SMB features are enabled by default and some require additional configuration.
| This functionality: | Requires enablement: | Is supported in ONTAP 9 for these SMB versions: | ||||
|---|---|---|---|---|---|---|
| 1.0 | 2.0 | 2.1 | 3.0 | 3.1.1 | ||
| Legacy SMB 1.0 functionality | X | X | X | X | X | |
| Durable handles | X | X | X | X | ||
| Compounded operations | X | X | X | X | ||
| Asynchronous operations | X | X | X | X | ||
| Increased read and write buffer sizes | X | X | X | X | ||
| Increased scalability | X | X | X | X | ||
| SMB signing | X | X | X | X | X | X |
| Large MTU (enabled by default beginning with ONTAP 9.7) | X | X | X | X | ||
| Lease oplocks | X | X | X | |||
| Continuously available shares | X | X | X | |||
| Persistent handles | X | X | ||||
| Witness | X | X | ||||
| SMB encryption: AES-128-CCM | X | X | X | |||
| Scale out (required by CA shares) | X | X | ||||
| Transparent failover | X | X | ||||
| SMB Multichannel (beginning with ONTAP 9.4) | X | X | X | |||
| Preauthentication integrity | X | |||||
| Cluster client failover v.2 (CCFv2) | X | |||||
| SMB encryption: AES-128-GCM (beginning with ONTAP 9.4) | X | X | ||||