I was working on a system with a PCI IDE card and wanted the drives to have certain labels. I wanted the system drives to be sda and sdb with the drives attached to the card to be sdc and sdd. I looked for information but didn't come up with much that was useful. However I was able to figure out that by modifying the file `/etc/initramfs-tools/modules` and specifying the modules for the drives in the correct order and then running `update-initramfs -u -k all` I was able to get the behavior I wanted. I'm not certain if this is the optimal solution but I suspect that it may be.