Basic Ghosting Problem

[comedydave]

Hi all,

I have just come back after an enforced Christmas break (damn caretaker making me use my holiday, coz he is off)

I am attempting to recast a few machines in one of our IT rooms.

 

We do not use console as the network manger cannot justify its costs. So we use the old floppydisk boot method.

That is not where the problem lies however.

Because this is the furthest room away from our ghost server, we have installed GhostCast server on the higher spec teachers client machine in the classroom, and cast from there. I am casting a 30gb image to 2 machines and its coming out at 119MB/min. Ludicrously slow.

It is only casting through one 10/100 3com unmanaged switch, but the switch seems to go crazy.

I have checked the room (and entire floor) for loopbacks, turned all the other pc's on the floor off, and disconnected a cisco fasthub that runs one room further along the network.

 

Any thoughts?

[GlennT]

Hi ComedyDave,

When you say the switch is going crazy, do you mean on all ports or just the ones that are connected to the 3 machines [and uplink]?

Also, have you ghosted this way before or is this the first time you have tried it?

Cheers,

Glenn.

[comedydave]

Any machines that are turned on (i had most of the room on at one point)

It looks just like a network card jabbering, or a loopback.

 

We always use this method, and a 30gb cast usually takes about 20 mins, these just took 3 hours!

[comedydave]

Strangest thing. Just started another cast on 2 machines (i've taken to doing the room in pairs now) This one is hoofing along at about 300MB/min, which I can live with.

 

One singular cast i started before lunch is still crawling at 100. Same switch, same source machine, same source file, same grade cabling and same methods.

 

I think it may be a mixture of everything being cold after the christmas break (no caretaker in over christmas, so no heating) and the fact the clients are 4 year old celerons towards the end of thier lifecycle (infact being replaced as soon as PC World/NEC can deliver the replacements)

[GlennT]

Are all the machines that you are ghosting the same make/model?

It could be incorrect network card settings on the ghost bootdisk maybe?

[comedydave]

all identical machines.

Is it the nature of ghostcasting for packets to be sent to every machine on the network, as i have every machine in the room on now in an attempt to warm the room up a bit. And the 3com switch has every light flashing 10 to the dozen

[GlennT]

As far as I am aware, the client should obtain an IP address from DHCP then the GhostCast server sends and receives directly.

Presumeably, if the machines can access both DHCP & DNS ok, all should be ok.

Are you sure it is definately a switch and not a hub?

[Ric_]

I may be wrong on this but... if you are using multicast and your switches don't support the feature or are incorrectly configured, you will get an increased amount of traffic.

 

Does unicast speed it up at all?

 

Have you tried a different switch?

 

Of course the client may just have a slow hard disk or not negotiated the network speed correctly.

[comedydave]

3com baseline switch 2024 23 machines in the room

uplinked to "networx" baseswitch 2401f doing the other 8 and the about 10 other points on this floor.

 

I will give the unicast trick a try once this latest cast has finished.

[comedydave]

Unicast is coming out at about 350MB/min

But that is with a multicast going on aswell, so I will se when the multi cast has finished

[comedydave]

Settled off at about 450-500mb/min, and the switch is a lot quieter.

Cheers guys, we live and learn.

 

I think I will set the rest casting and go and find another job to do