Sorry to double post, but I was asked to explain in more detail how I managed to get Debian running on my PogoPlug Pro. As alluded to in previous posts, you basically do it by installing archlinux on the Pogoplug Pro first and then connecting drive with Debian on it instead of the drive where you have archlinux installed. There is a little tweaking of the Debian drive that is necessary in order to get it to boot properly.
In my case, I also wanted to end up running Debian off of an external hard drive instead of a flash drive so there were a few additional steps necessary.
Assuming you have a factory default PogoPlug Pro. Install archlinux on the PogoPlug Pro following the instructions on this website. The exact webpage with the instructions is here:
http://archlinuxarm.org/platforms/armv6/pogoplug-provideov3.
We are going to be using Debian Squeeze. Refer to information on these websites: wiki
http://squeezeplug.eu/wiki/index.php/Main_Page and
http://squeezeplug.de/. Using a program called USB Image Tool, you extract a Debian Squeeze image onto a flash drive. Unfortunately, this tool cannot extract the image onto an external hard drive. So you have to use a flash drive. The detailed instructions are here:
http://squeezeplug.eu/wiki/index.php/Main_Page#Prepare_the_SD-Card_.2F_USB-Stick. You will be using the SqueezePlug image for Dockstar found here:
http://www.squeezeplug.eu/?download=10.
Once you have prepared the flash drive with the SqueezePlug/Debian image, you can connect it to the PogoPlug which should already be running archlinux. Archlinux should automount the Squeezeplug at /dev/sdb1/. Follow the instructions in post #619 on this forum:
http://forums.slimdevices.com/showthread.php?t=85285&page=62. Please read that entire post as the instructions are posted in a few segments. You will definitely need to do what is labelled as "Update 1" (setting your mac address) and may or may not need to do "Update 2" depending on whether or not you want to use wireless. I personally disabled wireless since I've read that the PogoPlug Pro has less resources to work compared to its counterparts so I figured it would be a good idea to disable wireless. It appears that "Update 3" is no longer necessary as it has already integrated into the process. If you followed all of the steps properly, you should be able to shut down the PogoPlug Pro and reboot with only the SqueezePlug/Debian flash drive connected. It should boot right into Debian. You can stop there if you wish. I, however, wanted to install Debian on an external hard drive rather than on a flash drive.
Plug the external hard drive you plan to use to run SqueezePlug/Debian into the PogoPlug Pro. SSH into the PogoPlug Pro. Type 'setup' to start the SqueezePlug Server GUI. It first asks what type of device it is running on. You will choose the first option which is Dockstar. I can't remember if it kicks you back to the command prompt or takes you back to the GUI. If you are in the command prompt, type 'setup' again to restart the GUI. Go to the "Misc Miscellaneous" menu option. From the Miscellaneous Menu, go to the "SP_to_HD Install SP-Server to an USB-HD." This will start the process of installing SqueezePlug/Debian onto the attached external USB hard drive. Unfortunately, this newly prepared drive will not actually be bootable.
So shut down the PogoPlug Pro and reconnect the drive where archlinux is installed. Reboot the PogoPlug Pro. SSH into the PogoPlug Pro. Connect the SqueezePlug/Debian flash drive and the newly prepared non-bootable SqueezePlug/Debian external USB hard drive. If you connected them in this order, the flash drive should be /dev/sdb1 and the external hard drive will be /dev/sdc1. I ran the following command to copy the files from the flash drive onto the external drive.
mkdir /a
mkdir /b
mount /dev/sdb1 /a
mount /dev/sdc1 /b
cp -R /a/* /b
cd /
sync
umount /a
umount /b
rmdir a
rmdir b
Then I shutdown the PogoPlug Pro and rebooted it with only the SqueezePlug/Debian external USB hard drive connected and it booted properly from the external hard drive. You can then setup whatever servers you like in Debian. The SqueezePlug Server GUI can help you set up some of the more popular options or you can set them up manually yourself. Have fun with your new Debian PogoPlug Pro!