iscsi and HVM

iscsi and HVM

[James Harper]

If I use a block-iscsi script to handle the connection of an iscsi
volume, I can use the iscsi: prefix in my config file. Qemu doesn't like
this though, even though it's just a plain raw block device. Is there
something I can do in the config to persuade qemu to be happy or do I
need to modify the source?

Thanks

James

Re: iscsi and HVM

[Konrad Rzeszutek Wilk]

On Thu, Aug 18, 2011 at 02:12:59PM +1000, James Harper wrote:
> If I use a block-iscsi script to handle the connection of an iscsi

What script is that?
> volume, I can use the iscsi: prefix in my config file. Qemu doesn't like
> this though, even though it's just a plain raw block device. Is there
> something I can do in the config to persuade qemu to be happy or do I
> need to modify the source?
> 
> Thanks
> 
> James
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel

RE: iscsi and HVM

[James Harper]

> 
> On Thu, Aug 18, 2011 at 02:12:59PM +1000, James Harper wrote:
> > If I use a block-iscsi script to handle the connection of an iscsi
> 
> What script is that?

This one
http://lists.xensource.com/archives/html/xen-devel/2007-11/msg00782.html
or at least very similar (can't find the original URL I copied it from).
I think I had to change the -a's to -b's so it detected if the block
device was already attached.

I have solved (worked around) the problem by modifying the script to
convert the 'iscsi' to 'phy' in xenstore once the block-iscsi script was
done with it.

I think it would be better if there was a separate 'format' for qemu
used was different to the 'type' that the block-* scripts need to use,
even if the block-* scripts had to update it. So 'iscsi' would have a
'format' of raw or phy or whatever it needs, as would 'drbd'.

James

Re: iscsi and HVM

[Konrad Rzeszutek Wilk]

On Fri, Aug 19, 2011 at 12:01:41PM +1000, James Harper wrote:
> > 
> > On Thu, Aug 18, 2011 at 02:12:59PM +1000, James Harper wrote:
> > > If I use a block-iscsi script to handle the connection of an iscsi
> > 
> > What script is that?
> 
> This one
> http://lists.xensource.com/archives/html/xen-devel/2007-11/msg00782.html
> or at least very similar (can't find the original URL I copied it from).
> I think I had to change the -a's to -b's so it detected if the block
> device was already attached.
> 
> I have solved (worked around) the problem by modifying the script to
> convert the 'iscsi' to 'phy' in xenstore once the block-iscsi script was
> done with it.

Ah, never did that. Looks like you would need to write the support in
'xl' to actually look for those types of non-common backends and execute them.

> 
> I think it would be better if there was a separate 'format' for qemu
> used was different to the 'type' that the block-* scripts need to use,
> even if the block-* scripts had to update it. So 'iscsi' would have a
> 'format' of raw or phy or whatever it needs, as would 'drbd'.
> 
> James
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel

RE: iscsi and HVM

[James Harper]

> 
> On Fri, Aug 19, 2011 at 12:01:41PM +1000, James Harper wrote:
> > >
> > > On Thu, Aug 18, 2011 at 02:12:59PM +1000, James Harper wrote:
> > > > If I use a block-iscsi script to handle the connection of an
iscsi
> > >
> > > What script is that?
> >
> > This one
> >
http://lists.xensource.com/archives/html/xen-devel/2007-11/msg00782.html
> > or at least very similar (can't find the original URL I copied it
from).
> > I think I had to change the -a's to -b's so it detected if the block
> > device was already attached.
> >
> > I have solved (worked around) the problem by modifying the script to
> > convert the 'iscsi' to 'phy' in xenstore once the block-iscsi script
was
> > done with it.
> 
> Ah, never did that. Looks like you would need to write the support in
> 'xl' to actually look for those types of non-common backends and
execute them.
> 

It's only qemu that has a problem with it.

James