Grub2 reinstall help

I have openSUSE 13.1 on sda1 (root) and sda2 (home), CentOS on sda3, Mint on sda4, and a swap/boot partition (according to fdisk). I would like to get rid of CentOS and Mint and reclaim the space.
Mint installed grub to sdaa let’s call it and when I format over Mint’s partition 4 and zypper remove grub2 and reinstall grub2 to sda and run grub2-mkconfig I get the grub prompt of sadness.
I dont want to back-up, format everything and reinstall just openSUSE, I should be able to do this right? What am I missing?
edit I should mention that openSUSE exists on two btrfs partitions that are part of a logical partition.
TIA

Start with showing “fdisk -l” output.

Sure - will do when I get home. I kind of made up the drive numbers when I posted, but it’s the general idea. Thx.

Disk /dev/sdb: 80.0 GB, 80032038912 bytes, 156312576 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000aa8ed

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048   156312575    78155264   83  Linux

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes, 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: dos
Disk identifier: 0x0004ca73

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *  1941235712  1953523711     6144000   82  Linux swap / Solaris
/dev/sda2            2048   614402047   307200000   83  Linux
/dev/sda3       614404094  1414543359   400069633    f  W95 Ext'd (LBA)
Partition 3 does not start on physical sector boundary.
/dev/sda5       614404096   698298367    41947136   83  Linux
/dev/sda6       698300416  1258293247   279996416   83  Linux
/dev/sda7      1258295296  1414543359    78124032   83  Linux

Partition table entries are not in disk order

Disk /dev/sdc: 80.0 GB, 80026361856 bytes, 156301488 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x00061d44

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1            2048   156301311    78149632   83  Linux

Disk /dev/sdd: 8166 MB, 8166703104 bytes, 15950592 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Working now…YAST…does bootloader config too…who knew? :wink:

sda1 is actually your swap
sda3 is an extended

you might want to reassess your info