svn commit: r287621 - in head/sys: cam/ctl conf modules/ctl

[Kenneth D. Merry]

On Thu, Sep 10, 2015 at 12:40:32 +0000, Alexander Motin wrote:
> Author: mav
> Date: Thu Sep 10 12:40:31 2015
> New Revision: 287621
> URL: https://svnweb.freebsd.org/changeset/base/287621
> 
> Log:
>   Reimplement CTL High Availability.
>   
>   CTL HA functionality was originally implemented by Copan many years ago,
>   but large part of the sources was never published.  This change includes
>   clean room implementation of the missing code and fixes for many bugs.
>   
>   This code supports dual-node HA with ALUA in four modes:
>    - Active/Unavailable without interlink between nodes;
>    - Active/Standby with second node handling only basic LUN discovery and
>   reservation, synchronizing with the first node through the interlink;
>    - Active/Active with both nodes processing commands and accessing the
>   backing storage, synchronizing with the first node through the interlink;
>    - Active/Active with second node working as proxy, transfering all
>   commands to the first node for execution through the interlink.
>   
>   Unlike original Copan's implementation, depending on specific hardware,
>   this code uses simple custom TCP-based protocol for interlink.  It has
>   no authentication, so it should never be enabled on public interfaces.
>   
>   The code may still need some polishing, but generally it is functional.
>   
>   Relnotes:	yes
>   Sponsored by:	iXsystems, Inc.

Wow, very cool!

Thank you for doing that, and thanks to iX for sponsoring it!

I was hoping that someone would pick up the HA work years ago when I put in
those stubs, and I'm very glad that you have done the work!

This will be great functionality for FreeBSD!

Ken
-- 
Kenneth Merry
ken at FreeBSD.ORG