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I'm curious to know if there are any tools for restoring disk images (or even transferring files) via multicast -- for any platform, especially if the project has source available -- where the multicast rate adjusts itself on the fly.

On the Mac, all multicast solutions I am aware of (such as Deploy Studio, and NetRestore before it) make use of multicast ASR (apple software restore), which has one glaring deficiency -- you have to set the multicast speed before you start sending a disk image over the network, and that speed is locked in. Either your clients can keep up and restore, or they can't*.

It seems to me that it must be possible for the multicast server to adjust the data rate, so you basically say "start sending this image", clients connect, and, if they can't keep up, they tell the server so it slows down. (Likewise, I'd expect the server to try speeding up if no client is having difficulties keeping up, and I'd expect to be able to cap that maximum throughput so that other network activities can go on without being resource starved.)

So, what sort of tools are out there? For Linux? Windows? Is there something for the Mac I've overlooked. [It just kills me that it is true that, by the time you get multicast up and going at a good speed to restore a lab, you could've unicasted the data to all the computers and be done.]

* There is a little leeway involved. I think individual clients can say, "I missed a little bit of data" and get it, and they can opt to listen in the next time the image is sent over the network, but on the whole, if they missed it the first go round, you have to image the machine again, and there is no time savings.

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up vote 1 down vote accepted

FOG does multicast disk imaging - excellent when you have a group of identical machines to image. Runs from a Linux server, can definitely image Windows and Linux clients, I have no idea if it works on Macs or not. I have no idea what voodoo is involved in Mac imaging. I have no idea if they can PXE boot.

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They do netboot. (I believe it is based on PXE booting). – Clinton Blackmore May 21 '10 at 0:35
Unfortunately some silly company chose to name it's product line with the same name as a network terminology acronym, so stronger Google-fu than mine is required to determine an answer without specifically asking the FOG people. But the ability to netboot is a good start (unfortunately NTFS is the only partition type that's highly compressible by FOG so far). – Andrew May 21 '10 at 2:04
FOG uses something called UDPcast to do the multicast imaging. (It will also let you specify a queue size for unicast imaging. Cool.) SystemImager, Flamethrower, and PLD Rescue CD also use UDPcast. It appears that UDPcast can also broadcast instead of multicast, and that SystemImager believes that using Bittorrent works better than multicasting! It is not clear to me yet that the rate is adaptive, but these were definitely the sort of tools I was looking for. – Clinton Blackmore May 21 '10 at 14:52
I think you have the answer then. – Andrew May 25 '10 at 3:11

wds on windows 2008 r2 can do what your talking about.

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