I started downloading the Ubuntu DVD image and it said it would take 10 hours:

[tdh@kanigix isos]> wget http://mirror.mcs.anl.gov/pub/ubuntu-iso/DVDs/ubuntu/edgy/release/ubuntu-6.10-dvd-i386.iso
--11:44:04-- http://mirror.mcs.anl.gov/pub/ubuntu-iso/DVDs/ubuntu/edgy/release/ubuntu-6.10-dvd-i386.iso          
          => `ubuntu-6.10-dvd-i386.iso'
Resolving mirror.mcs.anl.gov... 146.137.96.7, 146.137.96.15
Connecting to mirror.mcs.anl.gov|146.137.96.7|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 3,725,318,144 (3.5G) [application/x-iso9660-image]

 0% [      ] 2,078,715    100.13K/s ETA 10:09:22

This is on the desktop I built over the Christmas break. I routinely download the Solaris Nevada DVDs in a much shorter time, so I decided it must be the server was gating my performance. I wanted to download the DVD to a lab system at work and then download it to my home system. The SWAN dns looks hosed, so I couldn't do that. Instead, I started a download on my w2100z and was told it would take about 2 hours:

[tdh@warlock ~]> wget http://mirror.mcs.anl.gov/pub/ubuntu-iso/DVDs/ubuntu/edgy/release/ubuntu-6.10-dvd-i386.iso
--11:44:33--  http://mirror.mcs.anl.gov/pub/ubuntu-iso/DVDs/ubuntu/edgy/release/ubuntu-6.10-dvd-i386.iso
          => `ubuntu-6.10-dvd-i386.iso.1'
Resolving webcache.central.sun.com... 129.147.62.26, 129.147.62.30, 129.147.62.25
Connecting to webcache.central.sun.com|129.147.62.26|:8080... connected.
Proxy request sent, awaiting response... 200 OK
Length: 3,725,318,144 (3.5G) [application/x-iso9660-image]

1% [>   ] 67,507,355   541.70K/s  ETA 1:57:51

Since the two systems share the same link into my house and they are both running close to the same OS, I think they should have the same transfer speeds. I'm wrong. Why?

For kanigix, it could be:

• Minus - Crappy driver for my cheap NIC.
• Minus - DVD is on the same loop as my root HD.
  • By the way, I'm not writing to that disk.
• Unknown - Filesystem is a real ZFS pool of 4 disks.

For warlock, it could be:

• Plus - Proxy cache is filling faster than system is emptying.
• Minus - Going through VPN software.
• Plus - Optimized drivers for NIC.
• Unknown - Filesystem is a ZFS pool on 1 disk.

A rule of thumb I use is that VPN software imposes a 33% penalty on transfers. I could be wrong in this scenario.

Without looking at solid data, I think my next step would be to disconnect the VPN session, which will remove the first two points on warlock. If I'm still getting much better transfer speeds, I'll know to look at the drivers.

I can also look at transfer speeds to other systems in the house.

I also need to start learning some performance tools (probably dtrace) to see what is going.