Demo of SMB3 multi-channel with Samba

Version 3 of the SMB protocol was introduced by by Microsoft with Windows Server 2012. One of the compelling features is called “multi-channel” and gives the client the possiblitly to bind multiple transport connections to a single SMB session, essentially implementing client-controlled link aggregation at the level of the SMB protocol. The purpose of this is (at least) twofold: Increasing throughput, since the client can spread I/O load across multiple physical network links, and fault-tolerance, because the SMB session will be functional as long as one channel is still functional.

A Samba-implementation of multi-channel is still work in progress, but already rather advanced.

Here is a screencast demo of how that already works with latest WIP code:

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git: rebasing all commits of a branch

I have been searching for this feature a bit, so I note it down here for easier retreival…

Interactive rebasing (git rebase -i) is one of the most awesome things about git. Usually my call pattern is git rebase -i COMMIT1. This will present all commits of the current branch after COMMIT1 in the rebase editor. I.e. with this syntax, you always need the parent commit of the first commit you want to see in rebase. But sometimes one needs to interactively rebase all commits, e.g. when preparing a new branch before publishing it.

After playing with inserting a “x false” as the topmost line in the rebase editor, which works, I now found that git (of course :-) ) has a syntax for this:

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Running Debian Squeeze as libvirt/kvm Guest on Ubuntu

I struggeled for a while with Debian Squeeze, trying to persuade it to run as a libvirt/kvm guest on my Ubuntu 12.04 host. After successful installation, the guests failed to boot the kernel with the messages:

Loading Linux 2.6.32-5-amd ...
unaligned pointer 0x8ebf0002
Aborted. Press any key to exit.

For my own reference, I record here the solution I just found after trying all sorts of things like installing different versions of grub into the virtual machine:

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Samba Team Visits Microsoft For SMB2.2 Interop Event

In the week of February 27 to March 2, 2012, a few Samba developers accepted an invitation by Microsoft and attended an SMB2.2 testing opportunity at Microsofts Enterprise Engineering Center in Redmond. Jeremy Allison, Steve French, Volker Lendecke, Chris Hertel, Christian Ambach, Matthieu Patou and I found our way to Redmond with Stefan Metzmacher participating to some extent via IRC and mumble. For me, the event was a big success, and I am happy that I finally made up my mind to go there.  This is my personal report.

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