OK, your result of sudo os-prober = /dev/sdb5:Linux Mint 12 Lisa (12):LinuxMint:linux,
it shows Mint 12 is at sdb5
Disk /dev/sdb: 320.1 GB, 320072933376 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 35088 281844328+ 7 HPFS/NTFS
/dev/sdb2 35089 38913 30724282 5 Extended/dev/sdb5 35089 38750 29414983+ 83 Linux
/dev/sdb6 38751 38913 1309266 82 Linux swap / Solaris
Number Start End Size Type File system Flags
1 32.3kB 289GB 289GB primary ntfs
2 289GB 320GB 31.5GB extended
5 289GB 319GB 30.1GB logical ext3
6 319GB 320GB 1341MB logical linux-swap(v1)
I also found "disk utility" which shows me graphically that my sdb 320GB data drive has a 31 GB container on it I'm assuming has Mint 12RC on it.
Yes, mint 12 is at sdb5 as indicated by os-prober
"Disk Utility" has an option "delete partition" which I'm tempted to use once I've highlighted that 31GB section. Would doing so remove Mint 12RC and make the 320 GB drive go from 289 back to 320 GB?
Would doing so endanger the data in the NTFS partition?
I have never used disk utility.
cannot help on the question.
I used gparted all the time in Linux OS for partitioning work.
To use gparted, on terminal, type sudo gparted, type password if asked, then gparted will open the graphical representation of your /dev/sda, first hard disk image.
navigate to change to /dev/sdb
then, move mouse pointer to /dev/sdb6, right click, choose delete, apply, it should delete the /dev/sda6
next, move mouse pointer to /dev/sda5, right click, delete it
then, move mouse pointer to /dev/sda2, right click, delete it
now your second hard disk had the 33G unallocated space.
finally if you want to merge these unallocated space back to the data partition which is /dev/sdb1,
click /dev/sda1, right click, choose resize/move, on a popup windows, drag the right border all the way to the extreme right, covering all the unallocated space, apply
at the end you are back to having only one partition with ntfs
Edit, as you are still running from Mint 11, please do one more thing
install grub onto /dev/sda
sudo grub-install /dev/sda