Question about deleting partitions on hard drive?

[Sharpghost6]

I don't think I know what I'm doing when it comes to this. I'll have two operating systems, when I won't to delete the one and keep the other, I always get a "grub error" message and can't boot it. Why is this? I just delete the partition using Gparted.

Usually they're both Linux system, but I also have a Windows/Linux system to, hoping to delete that Linux partition for a newer one.

[cpet]

Normally grub will complain if you remove a partition but you did not remove the stuff from grub

[oz]

Yep, cpet is right on the money... you'll need to reconfigure GRUB after you've made changes to your partition layout because GRUB doesn't know about those changes automatically.

[Sharpghost6]

Yep, cpet is right on the money... you'll need to reconfigure GRUB after you've made changes to your partition layout because GRUB doesn't know about those changes automatically.

How do I do that?

[oz]

How do I do that?

The best GRUB tutorials that I've run across are found at the following links (depending on the version of GRUB you are using):

GRUB bootloader - Full tutorial

GRUB 2 bootloader - Full tutorial

Your distribution probably has something about configuring GRUB on their wiki pages, as well.

[reginaldperrin]

I always get a "grub error" message and can't boot it.

After you do your deleting, try running:

sudo update-grub

This will force grub to update its lists of what OSs it knows about, and where they are or what drives.

Hope this helps.

[velikij]

After you delete a partition, you should first reboot into the Linux system you installed Grub from in the first place. Then, from that OS, you should update Grub:

sudo update-grub

If you are installing a new version of Linux in place of an existing one, just use the installer for the new Linux to handle partitioning. If the other OS on the computer is a Linux version using Grub2, you shouldn't need to let the new system's installer rewrite the Grub in the MBR, rather reboot into the OTHER Linux and run update-grub.

If the other OS which remains is Windows, do let the new Linux install Grub, and it will scan the disk and find both MS-Windows and Linux partitions, and set up Grub appropriately.

If it didn't boot, you need to reinstall Linux in a partition, and let the new Linux install and it should update Grub appropriately.

One thing you should not do (for Grub2) is to try to edit the files in /boot/grub. This is done by running update-grub. Manual changes in the grub config are done by editing /etc/default/grub and files in /etc/grub.d and then running update-grub.

I'm assuming this is GRUB2, not the 'legacy' GRUB.