Udpcast April 2008

udpcast@udpcast.linux.lu

8 participants
10 discussions

throttle output of udp-cast
by David Crider 23 Sep '08

23 Sep '08

Is it possible to do dynamically throttled UPDcast transmission? We need to throttle the data flow to a Logic Innovations IP encapsulator (with LI's documentation attached with their permission). The udpcast mutlticast address is considered a single route to the IPE. The IPE sends out flow-control messages (described in document) that shows how many bytes are available for traffic for each route every 100 milliseconds in a multicastand comes from a user specified multicast of its own. Attached is the LI document, again with the manufactures permission. Also, you can contact Theo Aukerman, taukerman(a)logici.com for any additional info. I'm asking these questions because IF this is possible, then this would be an almost complete framework for an open source Data-casting network, and can be used for over the air data-broadcasting from any DTV transmitter or any other system with null packets. I currently work as an engineer for a TV station that does data transmission, but would like to move to an open source model.

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Sender's timeout for waiting for receivers
by Dmitry Popov 23 Sep '08

23 Sep '08

Hi everyone, Please confirm my guess (or explain how to implement it). I need a "sender-timeout", a period of time while sender waits for receivers to connect, and if none are connected - sender exits without transmission. The only way to implement this is shell/perl/... script, which starts udp-sender with --min-receivers option and monitors its stderr. If no "Starting transfer" is found during specified period of time - it kills udp-sender process. Regards, Dmitry

2 1

Request - include netcat
by brian＠polibyte.com 23 Sep '08

23 Sep '08

Hi, It would be nice if netcat were included in the CD and PXE images. Busybox has a version, so adding it shouldn't take much. All the best, Brian

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udpcast for Fedora
by Richard W.M. Jones 04 May '08

04 May '08

I just put in a Fedora Review Request for udpcast, which is the first step towards getting udpcast included as a standard package in Fedora. If udpcast users could review and test this package and post their experiences (good or bad) to this bug it would be helpful: https://bugzilla.redhat.com/show_bug.cgi?id=443449 Rich. -- Richard Jones, Emerging Technologies, Red Hat http://et.redhat.com/~rjones virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into Xen guests. http://et.redhat.com/~rjones/virt-p2v

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Scaling udpcast
by Richard W.M. Jones 24 Apr '08

24 Apr '08

I'm looking at using udpcast to broadcast large disk images (10+ GB) to a very large network of machines (1,000-10,000 receivers) over a mostly switched, partially segmented gig-ethernet network. Needless to say, the network of machines is all production-critical and I cannot get access to perform real testing. However testing it on my home network I can see some potential problems: - If _any_ receiver is misbehaving or unreachable then this stops all transmissions. Is there a way to get udpcast to drop troublesome receivers in this situation (other than unicast)? - Has anyone used the --ttl option to multicast over routers? Does it work (the manpage is unclear)? Does it need special routers? - Any other scaling tips? Should I try to go for the full set of machines at once or break up the broadcast into groups of machines? If anyone has used udpcast on such large networks, can you share any experiences. Rich. -- Richard Jones, Emerging Technologies, Red Hat http://et.redhat.com/~rjones virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://et.redhat.com/~rjones/virt-top

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Big Problem with cloned MACs
by Pitt Leidner 21 Apr '08

21 Apr '08

Hi ML, happy to found this tool, I've got my first big problem with it. Using the multicast to clone a HDD to several Clients, the clients take the MAC of the onboard NIC (NVidia nForce). After that, the original MAC is gone and I'm not able to restore this. This fact has been a little difficult to find. Cause I thought, the MAC ist Part of the NIC, not of the HDD, which has been cloned. So how does it come? And even how can I overcome this? Any Idea would be appreciated, TIA -- yours sincerely Pitt

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Re: [Udpcast] Kernel 2.6.24
by Matthias Ehmann 19 Apr '08

19 Apr '08

Michael D. Setzer II schrieb: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Just a quick question. When you did the build, were you logged in as root? > Many of the special files only work with root. I've had some people make the > mistake of building with an id other than root. > Thanks for your reply. No this is not the problem. This was not the first kernel I built. ;-) Kernel 2.6.23 works successful under the same preconditions. But as already mentioned I had to back port the e1000e driver. I will have a look at the ISO you mentioned. Could you send the .config file for the 2.6.25 kernel? > > I've built many kernels on my g4l cd image, and include udp-sender and > udp-reciever on the cd image, but have only setup the g4l to be use the > reciever. You could see it those kernels would work. I haven't setup a PXE > with g4l, but others have. > > Latest version with even the 2.6.25 kernel is available at: > ftp://amd64gcc.dyndns.org/g4l-v0.25alpha10.iso > > >

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Kernel 2.6.24
by Matthias Ehmann 19 Apr '08

19 Apr '08

I need support for intel e1000e network adapters finally introduced with kernel 2.6.24. So I compiled a 2.6.24.4 kernel for udpcast. I created a initrd for PXE boot. Kernel and initrd are loaded and the computers start to boot but they always hang after a while throwing the message init: can't open "/dev/null": no such file or directory The problem also occurs on my VMware testing machine. I used the 2.6.23.12 kernel configuration from the udpcast homepage with the suggested changes for the new parts of the kernel. My current workarround is a back-port of e1000e support from 2.6.24.4 to 2.6.23.12. But I would prefer to use kernel 2.4.24 Is there anybody out there with a running 2.6.24 based udpcast? Best regards Matthias

1 0

udpcast receiver options
by Tom Carpenter 09 Apr '08

09 Apr '08

If I access a virtual console on the cast-o-matic PXE images I've generated, --rcvbuf is listed as a commandline option for udp-sender. The manpage for udp-sender suggests setting, "Try playing with the settings in /proc/sys/net/core/rmem_default and /proc/sys/net/core/rmem_max, i.e. setting them to a higher value" Does udp-receiver's "--rcvbuf" option modify rmem_default and/or rmem_max or some other value? -Tom C.

2 1

Include ntfsresize into initrd
by Jeff Michels 03 Apr '08

03 Apr '08

Hello, I would like to include ntfsresize into an initrd created by cast-o-matic. I compiled ntfsresize statically and uploaded the application to be included in the initrd. I'm pretty sure this is a busybox issue. ntfsresize appears in the initrd but I cannot execute it. I am not very familiar with busybox so any help would be appreciated. Thank you in advance. Jeff Michels Technology Support Specialist The School District of Beloit

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Udpcast April 2008