begin Friday 09 January 2004 15:10, Donald Teed quote:

Hello,

I just found a link to this wonderful looking package last night when reading a old thread on slashdot about "Ghost 4 Unix".

First of all, a big thanks for this effort. The world needs this solution in open source form, and you've done it!

Up to now, I've been using something like g4u, except based on KNOPPIX, to do the imaging over dd, ftp, wget, and gzip. It works well for small numbers of machines, but I'd like the solve the problem for imaging perhaps 30 to 40 at once.

I'm just at the initial stage of investigating udpcast, and reading over the web site for any instructions I may have missed...

So far I have these initial questions.

1. Is there a howto for disk cloning written already?

It's all on the website.

How to use the udpcast boot disks: http://udpcast.linux.lu/#useboot How to make the disks: http://udpcast.linux.lu/#makeboot

2. I don't see any reference to the steps required for creating the disk image file of the template machine, or is this not how it is done? That is, I have a template machine ready to clone, what are the steps to make an image file of the hard disk, that upd-sender can use? Should I continue to use my equivalent to g4u to upload a gzipped disk dump (dd) file by FTP?

This URL describes how to make the boot disks:

http://udpcast.linux.lu/#makeboot

If you want to make an udpcast tranfer to/from a file, use the command-line version of the machine were you want to store the file/read the file from:

http://udpcast.linux.lu/#cmdline

For instance, to get one machines image to a file, do the following:

[A] On the machine itself: boot up the udpcast floppy or CD, just like you would for a normal transfer. Chose sender [B] On the machine were you want to store the image file: launch "udp-receiver -f image-file"

For restoring such an image to a a bunch of receivers, just do the following: [A] On the machine where the image is, start "udp-sender -f image-file" [B] On the machines where the image should be restored to, boot up the floppy or cd, and chose receiver.

3. Will the linux kernel enable DMA on the hard drive? I found DMA

Yes, it does.

(via hdparm) made a big performance difference in my KNOPPIX based solution, but then some kernels seem to automatically enable DMA anyway.

I know. Some versions of Knoppix (or maybe even 3.3?) left DMA disabled. Argh!

As far as I know, the reason for this is that certain CD-Rom drives cannot handle DMA from/to CD. Certain Suse CDs also left DMA from/to CD off during installation.

Regards,

--Donald Teed

Regards,

Alain

Donald Teed wrote:

On Fri, 9 Jan 2004, Alain Knaff wrote:

...

For instance, to get one machines image to a file, do the following:

[A] On the machine itself: boot up the udpcast floppy or CD, just like you would for a normal transfer. Chose sender [B] On the machine were you want to store the image file: launch "udp-receiver -f image-file"

More examples in the documentation would probably help. When you say -f takes a file, it is difficult to know whether that means /dev/hda or something like /usr/templates/IBM_master_template.gz since everything in Unix is a file.

It is whatever you want to clone. In your case, it seems to be the template file that you want to send.

In the case of udp-receiver on the server, I'd think it should be something like /usr/templates/IBM_master_template.gz

I think you mean udp-sender on the server ...

Now the reverse trip, to make the clones...

The server would run something like:

udp-sender -f /usr/templates/IBM_master_template.gz --min-clients 20

(assuming i want it to start after all 20 machines have connected)

while the target machines would boot a floppy or off the PXE to launch the receiver built into it.

Do I have this right?

I've not used the floppy because it doesn't come with my SCSI driver, but you want the target file on the client to be something like /dev/hda. You'll also want to uncompress that image file before you send it, unless you're just trying to transfer the image itself as a file.

It is partly difficult to understand because of the floppy menu not forming a visible part of the udpcast source package and man pages. Coming from the g4u I am expecting a shell script and executables on the floppy, but I have yet to run it.

You have yet to run the floppy? It asks you what to do...

On Fri, 9 Jan 2004, Alain Knaff wrote:

...

[A] On the machine itself: boot up the udpcast floppy or CD, just like you would for a normal transfer. Chose sender [B] On the machine were you want to store the image file: launch "udp-receiver -f image-file"

[A] above implies that if there is a 'sender' option on the floppy, there is probably also a 'receiver' option. This is the one you'd want. On the server, I think you have the basic idea down. Again, not having used the floppy, I don't know if you can have the floppy udp-receiver pipe through gunzip before writing. You'll have to try it and see.

rgds, Chris