Consider this to be my vote for block-reconfigure working. I suspect it wouldn't take much work actually.
In retrospect, it's completely possible to concatenate devices at runtime using device mapper. It's the same thing that LVM does under the sheets. If you somehow got your root on a DM device (initrd maybe?), then you could live-modify it to add in another device you pass through. It's fraught with peril, but completely possible.
On Apr 7, 2008, at 9:56 AM, Florian Heigl wrote: 2008/4/7, Jayson Vantuyl <jvantuyl@xxxxxxxxxxxxxx>:
I think the developers have kind of let this one go.
Once upon a time, in addition to block-detach and block-attach there was
also block-configure. Block-configure supposedly told the inner DomU to
refresh its idea of the block device. It stopped working a while back, a
few people complained, it was never fixed.
I haven't tested it, but this would be the "right way" to do it...if it
worked.
that was highly enlightening...
block-reconfigure would have allowed to reliably resize storage without shutting down domUs (yes, yes, with pvresize or other rescans and of course a capable filesystem, but lets stick to the root issue). I used to concatenate filesystem images using dd skip=xx but never found a way to notify the domU of a successful change. add in the fact, that large numbers of [ phy:... or, even worse file: ] disk definitions tend to be unreliable and it would be REALLY great to get the feature back.
maybe we can start a little rally to make someone from -devel aware this is a NEEDED feature?
rgds, florian
-- 'Sie brauchen sich um Ihre Zukunft keine Gedanken zu machen'
-- Jayson Vantuyl Systems Architect 1 866 518 9275 ext 204 |