Re: [Nbd] nbd-client can't connect to named export from initramfs

[Wouter Verhelst <w@...112...>]

On Mon, Mar 19, 2012 at 05:56:13PM +0100, Wim Muskee wrote:
> On Mon, Mar 19, 2012 at 12:06 PM, Wouter Verhelst <w@...112...> wrote:
> > On Sat, Mar 17, 2012 at 09:45:39PM +0100, Wim Muskee wrote:
> >> I'm experiencing an odd nbd-client problem, I can't connect to a named
> >> export from inside an initramfs.
> >>
> >> On the server runs nbd-server (3.0) as a service, the
> >> /etc/nbd-server/config is as follows:
> >> [generic]
> >> [ltsp]
> >> exportname = /opt/ltsp-images/ltsp-dev-i686.img
> >> virtstyle = none
> >>
> >> The client initramfs contains an nbd-client from a nbd-3.0 install. It
> >> uses the 3.0.6 kernel (x86). The command it uses is:
> >> nbd-client 192.168.0.1 -N ltsp /dev/nbd0
> >>
> >> When it tries to connect, something fails in the negotiation:
> >> nbd: registrered device at major 43
> >> Negotiation: ..size= 4229768MBError: Exported device is too big for
> >
> > That claims it's a 4TiB export. That can't be right.
> >
> > What's the actual size of the file you're trying to export?
> >
> The actual size is about 350Mb. Perhaps it miscalculates the size
> under certain conditions.
> But still it's weird because it can connect when using port based exports.

Very weird, yes.

> >> me. Get 64-bit machine :-(
> >>
> >> When I boot the client normally, I can do the same command, and
> >> connect to the image without problems.
> >
> > That's even stranger. I'd think that if it doesn't work in initramfs, it
> > wouldn't work in the normal system, either.
> >
> > Which distribution is this?
> >
> Gentoo, using Dracut as the initramfs builder.

I don't have much experience with dracut. I know it exists and that it supports
NBD, but that's about it.

I'll try and set up a testing environment soon so I can try to reproduce
and debug this. Will get back to you after that.

-- 
The volume of a pizza of thickness a and radius z can be described by
the following formula:

pi zz a