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SMB 2 leases vs oplocks
posted by Jean-Francois Panisset  on July 18, 2016, 4:05 p.m. (4 years, 16 days ago)
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Recently updated some Samba servers to 4.2 (bundled with CentOS 7.2), and the release notes contain this interesting tidbit:

SMB2 leases
===========

The SMB2 protocol allows clients to aggressively cache files
locally above and beyond the caching allowed by SMB1 and SMB2 oplocks.

Called SMB2 leases, this can greatly reduce traffic on an SMB2
connection. Samba 4.2 now implements SMB2 leases.

It can be turned on by setting the parameter "smb2 leases = yes"
in the [global] section of your smb.conf. This parameter is set
to off by default until the SMB2 leasing code is declared fully stable.


Has anyone played around with this? Does it help? I found the following protocol level discussion of leases vs oplocks, but that doesn't say anything about real-world performance increase (if any):

https://blogs.msdn.microsoft.com/openspecification/2009/05/22/client-caching-features-oplock-vs-lease/

A bit of hubris in the concept of code being declared "fully stable"...

JF


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