grub and dual booting
 

hey guys, I just installed centos 6.4 to an old sata drive I had and added it to my windows machine. I changed my boot priority so that the centos hdd boots first- I know windows will never detect a partition other than a windows one.

now my dilemma is when it boots up it goes straight to centos, actually doesn't even give me a choice for repair mode or a grub screen for that matter(even though I have a /boot/grub/grub.conf)

is there a simple way to just get grub to search all drives and remake the conf file? I tried sudo grub-update and got a command not found(figured it wouldn't be so easy)

maybe deleting grub and installing grub2 would be a better option?

all info I seem to find is ppl using 1 drive and partitioning for both OS. I'd rather do it this way :P

Check the /boot/grub/grub.conf file for a timeout entry at the top. It may be set to zero which is why you don't see a menu.
If you see a menu with windows, you should be alright. If you don't, you will have to post more information on the number of drives/partitions and where each operating systems boot files are. Without that information, no one will be able to give specific info.

Looks like dev/sda1 is my windows boot partition.



Disk /dev/sdb: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xf40a6bdf

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sdb2 64 19458 155777024 8e Linux LVM

WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xa8a8a8a8

Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 102400 7 HPFS/NTFS
Partition 1 does not end on cylinder boundary.
/dev/sda2 13 50993 409497600 7 HPFS/NTFS
/dev/sda3 50993 121601 567158784 7 HPFS/NTFS

Disk /dev/mapper/vg_livedvd-lv_root: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/vg_livedvd-lv_swap: 8355 MB, 8355053568 bytes
255 heads, 63 sectors/track, 1015 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/vg_livedvd-lv_home: 97.5 GB, 97471430656 bytes
255 heads, 63 sectors/track, 11850 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

I am replying to this incase anyone who is having similar issues can see my solution.

in /boot/grub/grub.conf i entered the following

title Windows 7
rootnoverify (hd1,0)
chainloader +1


i put that as the first one so that it boots in windows after 5 seconds. I read that if windows does an update and restarts to linux it can crash your windows system(not taking the chance)

Is your entry a typo? There's no way that should work as (hd1,0) is the same as sdb1 when using Grub Legacy.

After installation I swapped boot priority in bios. So even though Linux is SDA its still in grub as SDB. I also thought that strange but since grub-update isn't an option as long as it works I don't mind.