backup hd partitions grub questions

[vbdanl]

hi. thanks in advance for any and all help and my apologies for how difficult this is to read. i have read several posts regarding backing up hard drives, grub, mbr, etc. but am just at the point of not knowing what to try next without hosing up both drives..
i have 2 hard drives, one is 120gb, the other is 160gb. i just use one at a time, and wanted to have the other be a backup that I could just plug in and use should i have a pwr failure or lighting strike or whatever.
i used dd to backup the 120gb to 160gb drive, then started using the 160gb drive full time and unplugged the 120gb. i didn't think i would be able to use dd to clone 160 to 120, so i copied individual partitions. i copied the data and linux distros i wanted to keep, but did not copy one distro i plan to overwrite, and also did not copy the mbr.
i now wanted to swap drives and start using the 120gb drive and disconnect the 160gb "backup".
fc9 was the newest distro to be installed on the 160gb drive and was copied using dd to the 120gb drive (as mentioned above).
Here is the problem:
i now try to boot the 120gb drive. first i notice the fc9 splash image does not appear, but instead i see a older "pretty colors" grub menu which had older distros listed.
it appears the partition with fc8 or ubuntu is being used to obtain the menu.lst file instead of the newer fc9 distro and partition. i copied the menu.lst file from the fc9 partition to the other partition, then rebooted. when i try to select fc9 it gives me a grub error (i think complaining about the uuid).
when i did the fc9 install and it then became the grub or boot default, is that info stored in the mbr, and will i be able to fix the problem by copying the 512 bytes of mbr from the 160gb drive to the 120gb drive?
guess i should also mention something else that puzzles me. when i do a "df" command it showed the mount points as sda1, sda2, etc - all sda just as i would expect.
after i used dd to copy sda partitions to sdb partitions, then rebooted, now df shows sdb for the mount points of the partitions that i copied, rather than sda. the one i did not copy still shows mounted as sda. does this sound "normal"?
i am not seeing that now since i only have the one drive connected.
thanks.

[vbdanl]

i am wondering if this command will copy the first 120gb of the 160gb drive to the 120gb drive and basically be a complete backup that should be bootable:
dd if=/dev/sda of=/dev/sdb bs=4096 count=234436545 conv=notrunc,noerror
any ideas on whether this should work?

[vbdanl]

still reading, and still changing my mind on how this should be done.
this is how i now plan to copy everything from the 160gb hd to the 120gb hd and start using the 120 as my working hd:
use dd to copy each partition
use dd to copy the first 446 bytes of the mbr

this should leave the partition info on the 120gb drive as it was, which should not have changed.
if anyone sees any problems with this approach, please feel free to speak up.. thanks.

[vbdanl]

after i copied the 446 bytes of the mbr i was able to boot into fc9. problem solved.

[Dies]

Originally Posted by vbdanl

problem solved.

Good to hear, just so you know it seems to me like Gparted is a much easier way to handle these types of operations since it's just point and click, copy and paste.

But then I've never been really comfortable with 'dd'. As far as grub I always just re-install instead of copying over.

[vbdanl]

how do you re-install grub?
i use gparted for partitioning a drive, but never used it for copying partitions from one hd to another.. guess i didn't know it could do that.

[Dies]

Either one of these will work fine, for the first one just ignore the rescue disk thing and use the install DVD by typing 'linux rescue' at the prompt - if using the liveCD method just make sure you set your "root ()" to the grub you want to restore.

http://fedoranews.org/contributors/bob_kashani/grub/

https://help.ubuntu.com/community/Re...tallingWindows

Yeah, cloning partitions with Gparted is really easy and you don't have to do any math you just select the partition right click and copy then select the drive you want and paste it - it has to be unallocated space, I used Gparted to "clone" a fresh activated XP install so now if I ever need to re-install, it's just a quick copy and paste from sdb to sda.