Set OS X Server to Deny SMB 3 Connections

Sometimes an OS X Server will have very poor SMB file sharing performance – whilst I haven’t been able to ascertain with 100% certainty what causes it, something that may be a factor is the use of SMB 3 connections over SMB 2.

SMB 3 connections can be signed and encrypted, and this can put a significant amount of overhead on the server.

To disable SMB 3 at the server end, type the following in to Terminal

sudo scutil --prefs
get /
d.add ProtocolVersionMap # 2
set /

Info from

This article was posted by Kai Howells. If you liked this content and have any technical work in the Melbourne area, say hello via my contact form or give me a call on 0419 361 653 - I cover most of the greater Melbourne area and my rates are competitive.

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