[sheepdog] [PATCH RFC] add support of sheepdog backing store

[Hitoshi Mitake]

At Fri, 27 Sep 2013 01:37:30 +0900 (JST),
FUJITA Tomonori wrote:
> 
> On Thu, 26 Sep 2013 11:59:18 +0900
> Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp> wrote:
> 
> > This patch implements a new backing store support for sheepdog, distributed
> > storage system initially designed for QEMU
> > (https://github.com/sheepdog/sheepdog). With this patch, sheepdog can support
> > iSCSI protocol, so hypervisors other than QEMU/KVM and native OSes can use
> > sheepdog as their block devices. The new --bstype is "sheepdog".
> > (This patch is a refinement of tgt's sheepdog branch.)
> > 
> > This patch still has some todos and would have bugs, but I'd like to post it for
> > keeping this patch small and getting feedback in early stage.
> 
> Some might say this had better to be a dynamic loadable
> library. Either is fine by me because it doesn't depend on any
> original C header files.

I'm ccing people who would be interested in modular backing
stores, Ronnie Sahlberg and Andy Grover. I think the sheepdog backing
store support doesn't have to be a module because it doesn't create
any new dependencies. Any comments?

> 
> > Major todos:
> >  - exploiting multithread support of tgt
> 
> It has been a long time since I wrote any sheepdog code so I can't
> recall the details but this backing store can use only a single
> connection even if this uses tgt multithread feature?

Yes, multithreading seems to cause some problems. I'll fix it in the
near future.

Thanks,
Hitoshi