Re: [Qemu-devel] [RFC V5 03/11] quorum: Add quorum_open() and quorum_close().

[Benoît Canet]

Le Monday 27 Aug 2012 à 11:59:34 (-0600), Eric Blake a écrit :
> On 08/27/2012 01:30 AM, Benoît Canet wrote:
> > Valid quorum resources look like
> > quorum:threshold/total:path/to/image_1, ... ,path/to/image_total
> > 
> > ',' is used as a separator to allow to use networked path
> 
> Isn't this a step backwards?  After all, on the command line, we would
> have something like:
> 
> -drive file=quorum:...,readonly=on
> 
> but if the 'quorum:...' portion contains commas, then the qemu option
> parsing requires you to write those commas as doubled.  Which means to
> escape those commas for _both_ quorum: processing _and_ qemu command
> line parsing, I'd have to write:
> 
> -drive "file=quorum:2/2:path/to/image\\,,1,,path/to/image\\\\2,readonly=on"
> 
> to use the two files:
> path/to/image,1
> path/to/image\2
> 
> with appropriate shell, qemu, and quorum escaping.  Using : rather than
> , as the separator between quorum: elements was a bit simpler, since I
> don't have to type double commas for every single comma to be taken by
> the quorum parsing, escaped or not.
> 
> > '\' is the escaping character for filename containing ','
> > '\' escape itself
> 
> s/escape/escapes/
> 
> > 
> > On the command line for quorum files "img,test.raw", "img2.raw"
> > and "img3.raw" invocation look like:
> > 
> > -drive file=quorum:2/3:img\\,,test.raw,,img2.raw,,img3.raw
> > (note the double ,, and \\)
> 
> Yes, that's what I'm worried about.

I was following an idea of Blue Swirl.

You will have to use \\ on the command line.
':' can be used instead of ',' but it won't work
with networked urls.

> 
> -- 
> Eric Blake   address@hidden    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>