I just reread my post's beginning, and it is odd, but I will leave it and add this to the top.
First: I do not have a WEII nor have I ever logged in to one or opened one up. These are the procedures I would have taken to try to make a backup/recovery if I were to have gotten one of those when I got my deals on the WE 500GB. (Hence I had the resources to get familiar with one prior to attempting my backup of a never-booted one.)
I believe the files are the same for the WE and WEII, just the raid is not detected or mounted because the drives actually need to be configured as raided. You will put the boot loader on the drive with the longer cord connected to it and setup the raid to boot the primary drive (longer cable) in the event of a raid mount failure. Linear raid mode is probably what you will be doing.
Follow the links I posted below, read them, don't necessarily follow word for word, but adapt it. (The gentoo one's will probably help the most)
To make the raid and configure you will need both drives in your desktop at the same time.
You may have luck with hotswapping, like someone I read on the forum had, but they had other issues, that may have been resolved if they properly ran raidhotadd instead of trying to mount.
Good luck with your journey.
First make sure when you backup the mbr, you backup the proper drive. (I accidentally had done my real harddrive instead of the mybook one in the procedure's steps.)
I believe the actual files and firmware is the same… the MBR may be slightly different.
What I think would need to be done, is to read the fstab of a working mybook we II, I think it will detect the partitions as ext3 (linux_raid_member) or something different from my original ones.
You will need both drives in to mount the raid and capture software raid configured between them to start. (I am not sure what the WE II uses/supports)
From other's posts the drive connected to the longer cable is the one that it initially boots from prior to the raid being mounted.
But I believe the software raid was made using mdadm and mkraid, and the reason the mybook does not recognize past recovered mybook we2 is because people are just restoring parts, try making a raid small for boot and necessary partitions and make a storage partition on each drive of equal size and raid them together via software there. Then follow the rest of the steps for the data partition raid… same size may not be necesary if linear raided.
This guide is general to linux, but will probably do what you need…
Gentoo Setups with Raid (these will probably help the most, due to the nature of the mybook recovery)
gentoo software raid partition instructions
Installing_Grub_onto_both_MBRs where it explains creating a fallback mount if reading of the drives fails to mount later as a raid.
discusses how to take an already setup os and move it to software raid
Migrating a Linux boot partition to RAID-1
Like I said, I do not have a WEII, and have never actually looked in one or used logged into one, so this is all speculation.
My reasoning of thinking the files are the same and its just partitions raided needing to be done, is that there is only one firmware source released by wd.
BTW, someone a while ago who installed debian lenny on the weII did get raid working, but never posted how he did.
You may need to (do the hot load option and configure the raid via command line or with raidhotadd) quick tut that shows an example of raidhotadd
These links are not designed for the mybook's but they should help… and if you can make sense of the instructions and what I am trying to convey to you, I feel you will probably be able to figure it out.