Debian installation on Dell 1950 machines worked great for me, until I got my shining new PERC 5/i and SAS disks.

After some searching on the internet and figuring out a few things I found this to work.

This solution works for me on all new Dell machines we got.

• Insert Debian Netinst CD in your Dell machine, and power it up.
• Select country/language.
• When configuring network, please note that Gb1 is eth1 and Gb2 is eth0 (reversed order).
• Partition hard disks as you like and install your system as usual (I always choose Standard System only).
• When you get the "Installation complete" screen, do not choose continue, but rather switch to another console ().
• In console, do the following steps (it's good if you understand what you are doing, but my guess is you are not installing any servers without understanding this, so I will not elaborate them).

• mkdir /tmp_target
• mount /dev/sdb1 /tmp_target
• chroot /tmp_target
• echo "megaraid_sas" >> /etc/initramfs_tools/modules
• update-initramfs -u
• in /etc/fstab replace all /dev/sdbX with /dev/sdaX (/dev/sdb1 with /dev/sda1,...)
• in /boot/grub/menu.lst replace all /dev/sdbX with /dev/sdaX
• grub-install /dev/sdb (because it's still dev/sdb in the install, it will change later :)
• exit
• umount /tmp_target
• switch back to installation ()
• press continue

You might have noticed that the actual key to the entire process is megaraid_sas driver, which is not loaded by default. With some luck you should have a running Debian Etch on your Dell machine now!