Re: [9fans] Xen 3.0.3

> How are you doing networking? bridged or routed? have any handy[color=blue]
> scripts I could see?[/color]

I haven't changed anything in the scripts which are installed
by Xen, and it "just works" for me. It seems to be bridged - the
guest's virtual ethernet address is exposed to the outside world
by the host. I just run ip/ipconfig on the virtual Plan 9 machine,
and it's given an IP address by my normal dhcp server running
on another machine.
[color=blue]
> Do you run venti in its own domain?[/color]

No, so far I have only tried a single Plan 9 domain. I suppose
you might gain some security by putting venti in a different
vm but it would cost you some efficiency. I might try the
experiment some time.

On 12/3/06, Richard Miller <9fans@hamnavoe.com> wrote:
[color=blue]
> I haven't changed anything in the scripts which are installed
> by Xen, and it "just works" for me. It seems to be bridged - the
> guest's virtual ethernet address is exposed to the outside world
> by the host. I just run ip/ipconfig on the virtual Plan 9 machine,
> and it's given an IP address by my normal dhcp server running
> on another machine.[/color]

damn. It won't work for me at all.

Do you have your /lib/ndb/local handy? Or does the installed one "just work".

More linux distro diffs, I bet: what did you install under?

can you do an ifconfig -a and send it to me?

thanks

ron

I am copying this xen stuff to the list as I think we need it in the archives.

I have followed the tutorial at
[url]http://www.magma.com.ni/moin/Plan9Tutorial/XenInstall[/url] and things are
indeed better -- my venti is up and alive.

But as always, the rub with xen is the networking.

xm list shows this:
[root@q rminnich]# xm list
Name ID Mem(MiB) VCPUs State Time(s)
Domain-0 0 906 1 r----- 196.5
plan9 2 96 1 ------ 89.9




and brctl shows this:
bridge name bridge id STP enabled interfaces
xenbr0 8000.feffffffffff no peth0
vif0.0
vif2.0

So things are nicely bridged together.

With a bridge, it is as though they're on the same wire. Sort of.

(for those of you who don't recall, a bridge was a two-port device
that could be used as a mac-level connection between two networks. I
used to use them to isolate clusers from a main network, such that
intra-cluster traffic did not bleed off to the backbone -- this was in
the days of 10 mbit ethernet.)

At the same time, Linux bridges don't work like the good old hardware
ones, I have a thread I found long ago between me and some of the xen
guys discussing this. ...

OK, so Plan 9 is domain 2, and hence vif2.0 is the dom0 side of it:
[root@q rminnich]# ifconfig vif2.0
vif2.0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link
UP BROADCAST RUNNING NOARP MTU:1500 Metric:1
RX packets:20 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:11520 (11.2 KiB) TX bytes:0 (0.0 b)

note that they only give it an IPV6 adress, and it runs NOARP, a few
funny bits there.

I also do this:
[root@q rminnich]# echo 1 > /proc/sys/net/ipv4/ip_forward


an ipconfig from Plan 9 side gets this:
[root@q rminnich]# tcpdump -i vif2.0
tcpdump: WARNING: vif2.0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on vif2.0, link-type EN10MB (Ethernet), capture size 96 bytes
21:06:16.033763 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 50:6c:61:6e:39:00, length: 548
21:06:20.032192 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 50:6c:61:6e:39:00, length: 548
21:06:24.043403 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 50:6c:61:6e:39:00, length: 548


etc.

Now my wireless router is 192.168.0.1. This linux host is
192.168.0.103. So in Plan 9 dom2 I do this:
ip/ipconfig -g 192.168.0.1 ether /net/ether0 192.168.0.99 255.255.255.0

So I make the router my gateway.

And I can now ping the 192.168.0.1, such fun.

Xen docs do recommend that you hardwire the IP for a domU, not use
dhcp, so I guess I'll do that.

What's amusing is that I can NOT ping the dom0 linux box ... i.e. the
box I am running on: tcpdump sez:
21:15:41.641627 IP 192.168.0.99 > 192.168.0.103: icmp 44: echo request seq 5857

So I've got a bit more setup to do. Once this sort of works, I will
upate the wiki.

ron