From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Schinagl Date: Wed, 05 Jan 2005 11:29:18 +0000 Subject: Re: Hotplugging ethernet cables. Message-Id: <41DBCF8E.4000509@ehv.tass.philips.com> List-Id: References: <41D74A49.2060607@are-b.org> In-Reply-To: <41D74A49.2060607@are-b.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org What about SATA? sata is hotpluggable. And then, what if we have an external hdd rack via USB with a hot plugable sata connector in that. (as long as we don't have external sata connectors on laptops/PC's sounds reasonable) Linux-hotplug would notice the USB event, while sata would have to deal with the hotplugging of the sata? Also what about firewire? does linux-hotplugging handle firewire aswell? just curious ... Kay Sievers wrote: >On Tue, 2005-01-04 at 11:44 -0600, Linas Vepstas wrote: > > >>A naive question re ethernet hotplug: what if its iSCSI? >> >>On Sun, Jan 02, 2005 at 01:43:32AM +0100, Kay Sievers was heard to remark: >> >> >>>On Sun, 2005-01-02 at 02:11 +0100, oliver wrote: >>> >>> >>>>They mention ifplugd and even though this seems to work reasonably, I >>>>was wondering why hotplugging doesn't support ethernet hotplugging >>>>nativly? >>>> >>>> >>>Hotplug supports device add and remove, not state changes of hardware. >>> >>> >>> >>>>As I understand it the hotplugging daemon responds to events >>>>created by several devices, where the ifplugd polls and the device. >>>> >>>> >>>There is no such daemon involved in the hotplug handling. Hotplug is >>>driven by more or less stateless scripts invoked by the kernel. >>> >>>The network link state changes can be received on a netlink socket from >>>the kernel. These events are not hotplug events and don't really fit >>>into the model of linux hotplug. >>> >>> >>I can imagine a scenario where Linux has mounted a filesystem that >>is sitting on an iSCSI disk device. Thus, in many respects, this is >>analogous to a USB disk being plugged and unplugged. I also presume >>that iSCSI devices need not be just disks, but could be "anything", >>thus making the situation even more analogous to USB. >> >> > >Sure, it's similar in some aspects, but linux-hotplug is only a device >"add" or "remove" notification. Every event corresponds to a created or >removed directory in /sys. There is no such thing for a network link. > >If you add/remove the network device you get hotplug events. You don't >get hotplug events if you press a button of an USB device, which is very >similar to the network link state change. :) > >Some networking applications produce a very high event traffic for state >changes - like the zebra routing daemon, this is definitely not possible >to do with the event-by-forked-helper-application-hotplug system. They >use the netlink socket for good reason. What do you think is the problem >to get network layer events over netlink? It works nicely this way for a >long time. > >For a application level feature rich example, you may look how HAL is >collecting all available kernel events and offers a unified interface to >applications to subscribe to these events: > http://cvs.freedesktop.org/*checkout*/hal/hal/doc/spec/hal-spec.html?rev=1.36.2.5 > > > >>I'm also curious about plans for things like infiniband fabrics, >>which might be plugged/unplugged in various ways, which the OS might >>want to know about. Again, this seems clearly analogous to USB fabrics >> >> > >Never seen such a thing. :) > >Kay > > > ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt _______________________________________________ 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