From 15c37d6812088020d9d14355fc699788a5dc7b86 Mon Sep 17 00:00:00 2001 From: Michael Adam Date: Tue, 15 Mar 2016 21:56:44 +0100 Subject: [PATCH] WHATSNEW: document the experimental smb3-multi-channel feature Signed-off-by: Michael Adam --- WHATSNEW.txt | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/WHATSNEW.txt b/WHATSNEW.txt index 7011c12..6dd74ae 100644 --- a/WHATSNEW.txt +++ b/WHATSNEW.txt @@ -189,6 +189,53 @@ CTDB changes * All CTDB current manual pages are now correctly installed +EXPERIMENTAL FEATURES +===================== + +SMB3 Multi-Channel +------------------ + +Samba 4.4.0 adds *experimental* support for SMB3 Multi-Channel. +Multi-Channel is an SMB3 protocol feature that allows the client +to bind multiple transport connections into one authenticated +SMB session. This allows for increased fault tolerance and +throughput. The client chooses transport connections as reported +by the server and also chooses over which of the bound transport +connections to send traffic. I/O operations for a given file +handle can span multiple network connections this way. +An SMB multi-channel session will be valid as long as at least +one of its channels are up. + +In Samba, multi-channel can be enabled by setting the new +smb.conf option "server multi channel support" to "yes". +It is disabled by default. + +Samba has to report interface speeds and some capabilities to +the client. On Linux, Samba can auto-detect the speed of an +interface. But to support other platforms, and in order to be +able to manually override the detected values, the "interfaces" +smb.conf option has been given an extended syntax, by which an +interface specification can additionally carry speed and +capability information. The extended syntax looks like this +for setting the speed to 1 gigabit per second: + + interfaces = 192.168.1.42;speed=1000000000 + +This extension should be used with care and are mainly intended +for testing. See the smb.conf manual page for details. + +CAVEAT: While this should be working without problems mostly, +there are still corner cases in the treatment of channel failures +that may result in DATA CORRUPTION when these race conditions hit. +It is hence + + NOT RECOMMENDED TO USE MULTI-CHANNEL IN PRODUCTION + +at this stage. This situation can be expected to improve during +the life-time of the 4.4 release. Feed-back from test-setups is +highly welcome. + + REMOVED FEATURES ================ @@ -228,6 +275,8 @@ smb.conf changes -------------- ----------- ------- aio max threads New 100 ldap page size Changed default 1000 + server multi channel support New No + interfaces Extended syntax KNOWN ISSUES -- 2.5.0