Re: NetBSD and Remus support?

[Jean-Yves Migeon <jeanyves.migeon%free.fr@localhost>]

Le 10/09/2014 08:52, Brian Buhrow a écrit :
> 	hello.  We are looking at using Remus for some high availability
> applications.  We are a NetBSD shop and using Xen quite happily.

Hi Brian,

Sorry for such a late answer, for an unknown reason your mail appeared 
as read in my MUA...

> My
> question is whether anyone has looked at making remus work with NetBSD

None that I know of.

> and
> Xen and, if so, how much progress has been  made or analysis of the
> difficulty of making it work has been done?

That depends on the side you are on (dom0 or domU).

For dom0 the work is extensive, Remus requires checkpoint-based I/O so 
the system "knows" the state of the domUs, and replicate it to the 
fallback machine. This would require either porting them from Linux 
(IIRC they had a specific blktap driver for Remus) or implement our own.

For domU the work is minimal, memory replication should be done by 
hypervisor and xen tools.

AFAICT Remus does not offer disk replication directly, you have to rely 
on a DRBD/HAST equivalent so you can keep both file-systems in sync (I 
do not know if gluster would work in that case).

Cheers,

--
Jean-Yves Migeon