Date: Mon, 2 Jul 2007 00:55:22 +0200 From: Bernd Walter <ticso@cicely12.cicely.de> To: Martin Cracauer <cracauer@cons.org> Cc: freebsd-hackers@freebsd.org, ticso@cicely.de Subject: Re: pxeboot and /boot filesystem, share /boot/kernel Message-ID: <20070701225522.GB50157@cicely12.cicely.de> In-Reply-To: <20070701213540.GA83788@cons.org> References: <20070701181334.GA77427@cons.org> <20070701193640.GW50157@cicely12.cicely.de> <20070701213540.GA83788@cons.org>
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On Sun, Jul 01, 2007 at 05:35:40PM -0400, Martin Cracauer wrote:
> Bernd Walter wrote on Sun, Jul 01, 2007 at 09:36:41PM +0200:
> > On Sun, Jul 01, 2007 at 02:13:34PM -0400, Martin Cracauer wrote:
> > 4) Use different / on the same server filesystem with hardlinked /boot.
>
> Hmm, directory hardlinks through NFS server? But might do.
I ment the files in it hardlinked.
> I also considered hacking up the NFS server code to resolve individual
> symlinks of my choice. I like this feature a lot when serving samba
> shares to Windows clients to make stupid applications actually place
> stuff where I want it. But this solution is bad news if you rebase
> your NFS server.
Yes - too easy to forget.
> %%
>
> It has been pointed out to me that BSD used to have
> /etc/fstab.<hostname> back in the day. That seems to be easy enough
> to re-introduce given that pxeboot already set the IP address.
>
> However, it is somewhat hackey since in effect your first root
> filesystem (common for all clients) gets used only once for /etc/fstab
> and is only used to redirect to a new (indivual) root filesystem.
I have something quite similar with a bunch of NetBSD hosts.
Common / with different var partitions mounted by custom scripts and
not by fstab.
Since hostname was already set by dhcp at this point it worked.
> > 5) Use two / - one common for booting and a client specific.
> > loader.rc in common will overwrite rootfs.
> > But I'm unshure if you can get host specific data, e.g. MAC from net
> > interface.
>
> That is somewhat similar to /etc/fstab.<host> but would require the
> 4th to know about networking.
It does know the bootdev and I just checked the soruce and it even sets
variables:
common/dev_net.c: setenv("boot.netif.ip", inet_ntoa(myip), 1);
common/dev_net.c: setenv("boot.netif.netmask", intoa(netmask), 1);
common/dev_net.c: setenv("boot.netif.gateway", inet_ntoa(gateip), 1);
common/dev_net.c: setenv("boot.netif.hwaddr", temp, 1);
common/dev_net.c: setenv("boot.nfsroot.server", inet_ntoa(rootip), 1);
common/dev_net.c: setenv("boot.nfsroot.path", rootpath, 1);
No hostname, but IP and MAC.
You just have to use the variables in your own loader.rc to overwrite
the path.
You can fetch them with getenv:
s" boot.netif.ip" getenv
Well - my forth is too rusty, so I can't help on the if/setenv part.
> > 6) Don't install *.symbols and live with multiple file space usage for
> > the rest.
>
> Right but not sportish :-)
:-)
> Overall, I also need to keep in mind that some but but all of my
> diskless clients will have individual kernels and that I want the most
> elegant way to express this.
If you want you can select the kernel in your loader.rc as well...
> Or a per-host kernel setting in loader.rc which normally points to the
> common kernel but can point to an individual one. But as mentioned
> earlier, this is difficult to do if you / is already unshared, unless
> the loader can deal with NFS or tftp to load from a
> address:/boot/... location.
It can at least read any file from the already mounted NFS path.
No problem to read /boot/kernel.hostx/ instead of default.
Don't know if you can switch to another NFS path.
--
B.Walter http://www.bwct.de http://www.fizon.de
bernd@bwct.de info@bwct.de support@fizon.de
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