mass imaging with usb ethernet adapters

[tlarkin]

So,

Long story short there is a bug with USB to Ethernet adapters where if you set it to auto detect in the System Preferences, it will auto detect at 10 mbit. Well, since each Ethernet adapter has it's own unique MAC address I am thinking every time I plug a different one in, it generates a new preference.

Is there anyway to globally force 100baseT connection on all USB to Ethernet adapters? We use these for imaging and have about 100 of them for 5,500 Macbook Airs.

Any insight on this?

-Tom

[sean]

You could try:

networksetup

to get the device name of the hardware port and then:

ifconfig [device name] media 100baseTX mediaopt full-duplex

Sean

[tlarkin]

I got 100 usb ethernet adapters that are promiscuous though. They will get swapped around from machine to machine, and if I plug a different one in, will it get a new "blank" preference and get set to auto?

[stevewood]

Totally off the top of my head, and I'm not sure it would work. I'm
On Thu, Jul 21, 2011 at 8:40 PM, Thomas Larkin <tlarki at kckps.org> wrote:
assuming you only use these for imaging the machines, right? How about
adding all 100 adapters to each machine before imaging, and setting the
prefs on all 100? They'd get blown out once the image was on the machine,
right?

Again, I don't even know if it's possible to do it, but I thought I'd throw
it out there. :-)

Steve Wood
Director of IT
swood at integer.com

The Integer Group | 1999 Bryan St. | Ste. 1700 | Dallas, TX 75201
T 214.758.6813 | F 214.758.6901 | C 940.312.2475

[sean]

Tom,

I've tried on 10.6.8 (MacPro5,1) and 10.7 (MacBookAir3,1) with machines that had never used the adaptor before and both automatically set themselves at 100baseTX. It sounds like something else is wrong.

You've tried different ports, switches, cables, etc?

Sean

[tlarkin]

Well my mini is capped at 12MB/s throughput to all clients over AFP....and I had about 15 to 20 clients netbooting and block copying the image.

I just really need to speed this up.

[taugust04]

Hi Tom.

My apologies if my math is incorrect on this:

The Mac Mini is capped at 12MB/s, which converted from megabytes to megabits is 96mbps. Divide that by 20 clients and it comes out to 4.8 mbps per client. Unless you were multicasting that seem like an expected and acceptable speed for a block copy image restore.

Or maybe I'm misunderstanding the environment. Could you describe the topology and methodology for your imaging setup? Something else could be amiss besides your network adapters.

-- Ted August
Salve Regina University

[tlarkin]

Yeah the math does seem right is what I am realizing....I did think about setting up multicast but not sure if it would make a huge difference or not. Also, not quite sure the gigabit switches we are using to image.

-Tom

[tlarkin]

OK,

Glad to report I used a different switch, and throughput was just under 120MB/s which is 10x faster than before. I just imaged 20 in 23 minutes all with usb adapters and it is a TON faster. My guess is the different gig switch is smart enough to detect USB Ethernet and maybe ups the throughput to a higher rate? Another theory is that these switches are just better. They are all Netgear smart switches (which have some management options on them) so the newer switch runs 10x faster. Going to see if I can upgrade the firmware on the older switches.

So, looks like it now takes 23 minutes and change to do 20 instead of 4 hours.....which is a MUCH better image time. We can now get the 5500 Macbook Airs imaged before school starts!

-Tom

[#10]

It may just be me, but I have a few Mac airs (and as a result USB adapters) that don't autodetect the correct speeds 1 in 20 times. They were detecting 10 half on our HP gigabit switches.

Not sure if it was bad switches or just an autodetection issue but it's something to be aware of. I wrote a script to alert the user. Not sure what the best method would be in an netboot imaging scenario.

-Aaron

[bentoms]

Same thing I discovered with some belikin & netgear routers.

Regards,

Ben.

[#12]

Many years ago I had a similar issue with power mac's and cisco switches during imaging. It was a large clients site and they were not willing to help.

The solution was to configure the netboot image to set the ethernet port to manual and not to negotiate speed or duplex with the switch. Its a relatively easy fix.

Tomos