From mboxrd@z Thu Jan  1 00:00:00 1970
From: Matthias Schwarzott <zzam@gentoo.org>
Date: Fri, 13 Apr 2007 20:08:19 +0000
Subject: Re: Excluding some device types from persistent-net (xen, s390)
Message-Id: <200704132208.19301.zzam@gentoo.org>
List-Id: <linux-hotplug.vger.kernel.org>
References: <200704120944.10520.zzam@gentoo.org>
In-Reply-To: <200704120944.10520.zzam@gentoo.org>
MIME-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
To: linux-hotplug@vger.kernel.org

On Donnerstag, 12. April 2007, Matthias Schwarzott wrote:
> Hi there!
>
> I have a change to persistent-net behaviour, to exclude xen-devices, and
> s390-devices.
>

I thought even more about the persistent-net framework.

The problems appear in two different cases:
1. Random MAC addresses (as we for now only use by-mac as method)
This will lead to increasing numbers for the device after each reboot with =

different mac.

2. Devices that are ignored and does not add persistent-rules.

This leads to errors as soon as on a system there are devices which we try =
to=20
get persistent, and devices which we ignore (with the same prefix, e.g.=20
eth*).
As udev cannot rename the device as soon as the dest name is already occupi=
ed.
(ignored devices being eth1, and udev trying to rename eth2 to eth1 will le=
ad=20
to eth?_rename devices ...)

Possible solutions for different devices (restricting me to eth, will add n=
ew=20
mail about wifi stuff):


xen-devices:=20
# udevinfo -a -p /sys/class/net/eth0
=20
  looking at device '/class/net/eth0':
    KERNEL=3D"eth0"
    SUBSYSTEM=3D"net"
    DRIVER=3D""
    ATTR{weight}=3D"64"
    ATTR{tx_queue_len}=3D"1000"
    ATTR{flags}=3D"0x1003"
    ATTR{mtu}=3D"1500"
    ATTR{carrier}=3D"1"
    ATTR{broadcast}=3D"ff:ff:ff:ff:ff:ff"
    ATTR{address}=3D"00:16:3e:08:25:1d"
=20
  looking at parent device '/devices/xen/vif-0':
    KERNELS=3D"vif-0"
    SUBSYSTEMS=3D"xen"
    DRIVERS=3D"vif"
    ATTRS{devtype}=3D"vif"
    ATTRS{nodename}=3D"device/vif/0"
=20
  looking at parent device '/devices/xen':
    KERNELS=3D"xen"
    SUBSYSTEMS=3D""
    DRIVERS=3D""

Perhaps the KERNEL(S) attribute of the parent device can be used for=20
persistence (even though I don't know how the rule should look like) but=20
perhaps just KERNELS=3D"vif-0" will work. As I think the number refers to t=
he=20
(n+1)-th network interface declared in xen-conf for this domain. And that=20
should be constant, even if mac changes.
Better solutions for xen-devices?


s390: For s390 I don't know the facts, please others discuss if there is=20
something special necessary or not.

eth1394: Some users seem to have problems with eth1394, but the people I as=
ked=20
seem to have no problems with it (seem to have macs set and constant).

See this thread: "Problems with udev > 106 and multiple network cards"
Perhaps if just one device of this type appears we can persist it with=20
ATTR{type}=3D"24" in case no mac exists, ugly :(

Matthias

--=20
Matthias Schwarzott (zzam)

-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys-and earn cash
http://www.techsay.com/default.php?page=3Djoin.php&p=3Dsourceforge&CID=DEVD=
EV
_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel