[sheepdog-users] runtime requirements?

[Miles Fidelman]

In response to my query:
> Miles Fidelman wrote:
>> Hi Folks,
>>
>> I've long wanted to try sheepdog in a xen cluster - and kept running 
>> into the requirement to run qemu and KVM, which in turn requires 
>> hardware virtualization support - which some of the older machines in 
>> our cluster don't support.
>>
>> Am I correct in my reading of the documentation for the latest 
>> version of sheepdog that I can run the iSCSI target and access 
>> sheepdog block devices, without qemu or KVM?  Or am I missing something.


*Liu Yuan* namei.unix at gmail.com 
<mailto:sheepdog-users%40lists.wpkg.org?Subject=Re%3A%20%5Bsheepdog-users%5D%20runtime%20requirements%3F&In-Reply-To=%3C20140313052730.GC3925%40ubuntu-precise%3E>wrote

> we don't need hardware virtualization at all. We provide volume abstraction
> for QEMU. I think you can run sheepdog in dom0 in xen server if QEMU version
> is new enough. Even if your QEMU dosn't support sheepdog, you can export volume
> by sheepfs then run it as file for QEMU.
>
> >/  
> />/  Am I correct in my reading of the documentation for the latest
> />/  version of sheepdog that I can run the iSCSI target and access
> />/  sheepdog block devices, without qemu or KVM?  Or am I missing
> />/  something.
> /
> Yes, actually we are developing other interfaces like RESTfult kv storage and
> nfs backend.
and *Andrew J. Hobbs* ajhobbs at desu.edu 
<mailto:sheepdog-users%40lists.wpkg.org?Subject=Re%3A%20%5Bsheepdog-users%5D%20runtime%20requirements%3F&In-Reply-To=%3C5321BAF0.4040302%40desu.edu%3E>wrote
> No, that's correct.  I also have two nodes out of six that run sheepdog
> as storage units in my cluster.  They don't have virtualization support,
> but they have drives.

Thanks guys.  Looking forward to trying out Sheepdog.

Re. "we don't need hardware virtualization at all. We provide volume 
abstraction for QEMU.
I think you can run sheepdog in dom0 in xen server if QEMU version is 
new enough:"

I don't understand this at all.  As I understand it, QEMU is used in 
three scenarios:
a. provides a software virtualization (emulation platform)
b. provides the device drivers for KVM (which only runs using hardware 
virtualization)
c. provides device drivers for Xen, when Xen is running in hardware 
virtualization mode

But.. when Xen is running paravirtualized - Qemu isn't involved at all.

Since I'm running Xen paravirtualized (for speed in all cases, and for 2 
servers, because they don't have
hardware virtualization available), QEMU based drivers aren't available 
- hence my reasons for not
being able to use Sheepdog in the past.

iSCSI solves the problem.  So would NFS.

Thanks!

Miles




-- 
In theory, there is no difference between theory and practice.
In practice, there is.   .... Yogi Berra