trying exherbo again,

this time... i mean it! ;D
on booting, i get told "VFS: Cannot open root device "sda5" or unknown-block(0,0)", that my only viable "root=" choices are my cd drives, and a kernel panic - not syncing: VFS Unable to mount root fs on unknown-block(0,0)
^ that's the jist of the error output. here's a picture:
http://ompldr.org/vZ285Yg (took a while, ompldr's slow tnite)
it's not always exactly the same... since i've tried about half a dozen different kernels, and a mix of real_root and so on.
crazy thing is... i've had exherbo work already... albeit, not
this install, and not with the kernel i configured for it, but with a genkernel from an old gentoo... alas, that's not working on this exherbo install
(was previous install i had wiped, along with a load of other partitions, to dedicate the whole hd to exherbo... to force my hand in these situations not to simply give up and use another distro already installed).
i'll likely jump into attempting to configure another kernel for it, but i doubt that's going to resolve the problem. but maybe it will.
i'm using grub2 for the first time, and systemd for the first time, so no doubt i'm doing something wrong with one of these. i've already troubleshot a couple issues i was having in understanding grub2 (like partition letters no longer starting from zero), and when installing systemd, i did so following the instructions from exherbo, to the letter (mostly).
oh, another thing that i had considered may have been posing an issue, is that exherbo's root is on a logical partition, and there's an unused gap between the boot partition (sda3) and the extended partition of a couple mb. i've heard grub2's a bit thick when it comes to partition numbering when you've been removing partitions, so i had wondered if this could have been causing an issue, and have tried various sda4, 6, 7... just incase.
though with so many other things being tried, it's hard to know if there's a specific combination of options and other settings in the grub2 boot entry, that will allow a successful boot, of which i may have tried some, but not the complete set. i find this unlikely though, as when i successfully managed to boot into exherbo on my prior install, it was withusing just the default simple grub2 boot entry as provided in the exherbo install guide (changing to the correct drive locations of course). ... i am at a loss as to where to turn next.
so, a few attempts at google-fu later... and it's time to resort to linuxquestions. any hints or clues pointing in the right direction gratefully received.
and if not... i dont mind this just being another landmark/reminder of progress made so far. ^_^
thanks for reading.
