I have an HP server that I'm going to use as an imaging server. It's a 2.8GHz Xeon with a gig of ram and 5 scsi hard drives in a raid 5 configuration. I have a number of new Dell desktop PC's that I'm going to be imaging. They're P4 2.4 GHz w/ 1 80gig 7200 rpm ide hd and 512 mb of ram. The network we're using is isolated. We're using a cisco 6509 as the main switch with a gig uplink to the server. From there, we ran 4 network drops to where we image the desktops. Each drop has an 8 port linksys 10/100 switch and the desktop(s) to be imaged are hooked up to a linksys switch.

Here's what I have done to create an image on one of the Dell's

1) Zero out the hard drive dd bs=1024k if=/dev/zero of=/dev/hda

2) install windows xp on the system.

3) reboot the dell with the udpcast floppy image. I'm using an e1000 driver. I tell it to ghost /dev/hda. I choose lzop compression with no additional parameters. I then start the udpcast program as the send and it waits for the reciever (my hp server) to start.

4) start udpcast on the server. time udp-receiver -f dell_lzop.img The server starts and tells me that it has found a client so I hit enter again and the transfer starts.

The transfer averages about 15 mbits/sec at first. After about 5 min it starts dropping to around 1.6 mbit/sec. When it's the finished, the size of the image is just over a gig. The transfer takes about 30 min. Slice % on the sender ranges from .1% to .2% with a few intermittant timeouts.

Then to send the image back out to another dell PC.

1) boot up dell PC with udpcast floppy. I tell it to image /dev/hda. I'm still using the e1000 driver. I tell it to use lzop compression and set it up to be the receiver with no additional parameters.

2) start udpcast sender on the HP server. time udp-sender -f dell_lzop.img --half-duplex --max-bitrate 500m and hit enter.

The transfer runs at over 80 mbits/sec for about a minute and a half and slows down after 680 mbytes of the 1 gig image have been transfered. That's 2/3 of the image is transfered in a minute and a half!. But then the transfer slows to a crawl of about 600 kbits/sec. Once it slows down, the sender get's constant timeouts with a couple transmits in between. The slice % is around .3. The total image time is 71 minutes.

Anyone have any ideas on what I can do to keep this slow down from happening? I'm pretty sure I've ruled out the network as the problem. I tried doing a udp-sender -f /dev/zero and udp-receiver -f /dev/null and I can sustain 85+ mbits/sec for an indefinate amount of time on our 100mbit network. Are there any switches I should be throwing on the dell pc to keep it from bogging down when writing the image to the hd?