Software Basics of SMB Multichannel and Samba 4.6.x

zane

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Aug 22, 2013
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I am having a very difficult time finding examples and the Samba documentation seems to be out of date or I'm not finding what I need.

I do not have any question related to hardware I am fully aware of the hardware requirements my focus is on software only please.

My current setup is on RHEL 7.3 / CentOS 7 but even examples with Debian / Ubuntu would be very will received. I will compile 4.6.x latest.

What is the best Linux client for Multichannel? Config examples please.
Can Linux Samba be the Multichannel server ie Linux to Linux Multichannel? Config examples please.
Can Multichannel be implemented with out a domain?
Is there a requirement around having the NICs on separate subnets?
I am ok with using Windows as the Multichannel SMB server but am confused on if I should be using 2012 R2 or 2016 with my Linux client.
I have no issues on getting Windows to Windows SMB Multichannel working.

Thanks for any help as I've really gotten my self confused around all this and I do not think I am the only one.
 
Last edited:

RTM

Well-Known Member
Jan 26, 2014
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I think that the reason why you are not seeing multi channel documentation is that it is not considered production ready.
I did a little digging, the feature was added in 4.4 and marked as experimental, and I haven't seen any messages indicating that it isn't experimental anymore, suggesting that it still is.

The 4.4 release notes seem to suggest that you have to do the following:
In Samba, multi-channel can be enabled by setting the new
smb.conf option "server multi channel support" to "yes".
To answer some of your questions (partially at least), I doubt it is a good idea to use Linux with Samba as a server with multi channel.
With that in mind I think you will be forced to make the configuration files yourself (it seems to be just one flag in smb.conf though, so perhaps you can just set that and use a basic configuration).

I think you should ask yourself the question, why you want to use multi channel with Samba.
If it is to evaluate it, I suggest you try making the conf files yourself or perhaps (if no one else here has the answers) check out the Samba projects IRC or mailing list.
If it is for production use, I think you would be better off using Windows (at least for the server), especially since you are talking about compiling Samba yourself.
 

zane

Member
Aug 22, 2013
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I think that the reason why you are not seeing multi channel documentation is that it is not considered production ready.
I did a little digging, the feature was added in 4.4 and marked as experimental, and I haven't seen any messages indicating that it isn't experimental anymore, suggesting that it still is.

The 4.4 release notes seem to suggest that you have to do the following:


To answer some of your questions (partially at least), I doubt it is a good idea to use Linux with Samba as a server with multi channel.
With that in mind I think you will be forced to make the configuration files yourself (it seems to be just one flag in smb.conf though, so perhaps you can just set that and use a basic configuration).

I think you should ask yourself the question, why you want to use multi channel with Samba.
If it is to evaluate it, I suggest you try making the conf files yourself or perhaps (if no one else here has the answers) check out the Samba projects IRC or mailing list.
If it is for production use, I think you would be better off using Windows (at least for the server), especially since you are talking about compiling Samba yourself.
I have to use it due to bandwidth / throughput restraints that exist in the Cloud because teaming or bonding is not an option and ISCSI MPIO will work but it is heavy and I dont want to. I'm working with 200+ GB single file data sets so speed network throughput is a must so the single thread file transfer will transform into a multithread.

This a POC not production and I'm stuck trying to get this to work with Linux as the client and SMB Multichannel nothing else. I'm sure I will use Windows as the server but it would be nice to know if Samba would function as a multichannel server. Compiling Samba is not that bad at all but I would not be doing it if all the repo where not lagging on 4.4.x.

I have not gotten anywhere in the Samba mailing list so I may give the IRC a go. I figured there are plenty of cutting edge people in this forum that someone may have tried it.

I am aware of the below config flags in smb.conf. This has not done anything for me from the Linux client point of view on Ubuntu or RHEL.

Code:
server multi channel support = yes
aio read size = 1
aio write size = 1
If I do ever figure this out I'm going to write a paper on in layman terms because there are plenty of unanswered configuration questions about this tech. It is probably something so simple that I will kick my self I'm sure....
 

zane

Member
Aug 22, 2013
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This subject is locked down and absolutely no one knows jack **** about samba implementation of multichannel. I've tried the samba mailing list and IRC channel my questions are avoided like the dam plague everywhere. This thread is in the top 10 in google for "smb multchannel linux" simply crazy that is that impossible to do.

@RTM thank you for having the sack to post anything at all ;)
 

BLinux

cat lover server enthusiast
Jul 7, 2016
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This subject is locked down and absolutely no one knows jack **** about samba implementation of multichannel. I've tried the samba mailing list and IRC channel my questions are avoided like the dam plague everywhere. This thread is in the top 10 in google for "smb multchannel linux" simply crazy that is that impossible to do.

@RTM thank you for having the sack to post anything at all ;)
I feel you. Been there. There is always the source code.