What is this GRUB thing...

Installation and support for Oracle DB on CentOS.
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asad
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Joined: 2006/06/05 15:19:02

What is this GRUB thing...

Post by asad » 2006/06/05 15:28:06

hello,

I am installing centos with in addition to windows xp in my pentium III machine. there is plenty of space in partitioned disk ; infact every thing went without any problem until the installer greeted me with congratulations.. for installing centOS. It asked me to re-boot the machine. After that there is a single word on screen saying "GRUB _ " with blinking curson where i can not punchin anykey (or it dont show it to me) but after some keystrokes , i guess , keyboard buffer exhausted and started beeping at me! nothing is working now....

i guess this is boot loader problem, that cannot (somehow) guess what to load or ask; now what to do ( i'm new to U/L inx) world and this is driving crazy... i tried to start to install process again from scratch but eventually ended up with the same screen saying ... GRUB ...

can you guys help me out from here...

i'll be grateful..

thanks,
asad

hughesjr
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Location: Corpus Christi, Texas, USA
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What is this GRUB thing...

Post by hughesjr » 2006/06/07 11:34:26

Somehow the bootloader didn't get installed on the machine. It should have unless you choose "Do not install a boot loader", a none standard option.

Not sure how this belongs in the Oracle topic :-)

Boot from the CD-1 ... use the command:

[b]linux rescue[/b]

Select to have it mount your partitoins, and after it mounts your partitons and dumps you to the command line do:

[b]chroot /mnt/sysimage[/b]

the command [b]fdisk -l[/b] will tell you all your partitons ... you need to know which one is /boot (if it is seperate) and which one is / (that is root). If you have an LVM root, that also needs to be known.

The command [b]mount[/b] will also help you determine this.

Once you know where your /boot partiton is, (ie ... if you have windows is might be /dev/hda2, if you have CentOS in a seperate drive it might be /dev/hdb1, etc.) ... look in /boot/grub/Device.map and make sure that drive (hda, hdb, etc.) is listed in there ... example:

(hd0) /dev/hda
(hd1) /dev/hdb

hda1 (the first partiton on hda) would be (hd0,0) in grub ... hda2 is (hd0,1) in grub. hdb1 is (hd1,0), hdb2 is (hd1,1), etc.

Now enter the grub prompt with the command:

[b]grub[/b]

Now you are inside the grub prompt...here you need to install the boot loader. You will first do this (substitute the proper partition for your /boot partition):

[b]root (hd0,1)[/b]

then do

[b]setup (hd0)[/b]

if there are no errors, do:

[b]quit[/b]

then exit and exit to reboot.

Paul_E_T
Posts: 12
Joined: 2006/02/27 22:07:56
Location: Boondocks, Orlinda, TN, USA

Re: What is this GRUB thing...

Post by Paul_E_T » 2006/06/11 15:04:32

For HughesJR
I have experienced this problem several times without any knowledge of how it happened (until now). The GRUB screen on boot problem is not uncommon and a search at Google or Linux Questions dot org will show several help requests. I am willing to bet that this boot problem causes many people to reject Linux and is hurting the linux community since if one tries to dual boot and this happens many people have to wipe their disks and reinstall MS Win's. Not a nice thing to do and bad memories of a try to change to Linux. I tried two times with the same error and finally decided not to install linux on a newer machine. I had to purchase a copy of OEM win XP from HP a $30 copy cost for restoral, plus hours of download, plus downtime, plus data lost, plus agrevation, plus a red face, plus a machine not using Linux.
I believe the real problem here is the typical LINUX failure to communicate that has cost the linux community many followers. I do not recall that "do not install MBR" option but if there is one, it surely needs an inpact message about dual boot with other OS's and likely error message with more comprehensive documentation. You as an experienced user may not need it, but, think of the hundreds if not thousands of newcomers who needed the impact message and thus are no longer in the linux fold who now scuff at Linux.
Thank you for your good insight and knowledge.
Paul T.
In hope that this message encourages positive change.

DavidMD
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Joined: 2006/09/07 23:12:27
Location: Hermitage, TN, US
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Re: What is this GRUB thing...

Post by DavidMD » 2006/09/07 23:48:01

Hello, Paul!

[quote]
Paul_E_T wrote:
For HughesJR
...The GRUB screen on boot problem is not uncommon and a search at Google or Linux Questions dot org will show several help requests. I am willing to bet that this boot problem causes many people to reject Linux and is hurting the linux community since if one tries to dual boot and this happens many people have to wipe their disks and reinstall MS Win's. Not a nice thing to do and bad memories of a try to change to Linux. I tried two times with the same error and finally decided not to install linux on a newer machine. I had to purchase a copy of OEM win XP from HP a $30 copy cost for restoral, plus hours of download, plus downtime, plus data lost, plus agrevation, plus a red face, plus a machine not using Linux....
Paul T.
In hope that this message encourages positive change.[/quote]

Although GRUB is off-topic for a Linux thread, you make astute and valid points.

I was able to solve the dual-booting problem early this year, when I bought a used Dell Dimension 8300 from a coworker. (I had been dual-booting Linux and Windows XP Professional on a computer that I built myself.)

I am going to install Windows XP Professional on the Dell computer, which I don't anticipate using very much, and I now have my self-built computer as a Linux-only workstation. I realize that building or purchasing a second computer is not within everyone's budget, but it is not too difficult to find a slightly older, refurbished computer, which one can use for Linux or Windows, keeping the two operating systems on separate machines.

I have taken matters a step further, because of good luck. I won a refurbished computer in a drawing at my local computer store and I am installing CentOS on it in order to create a separate database server for Oracle 10g and MySQL. If I end up making a few messes setting up Oracle, I won't have to worry about corrupting my main workstation -- and, if all goes as planned, I can access the database server via my home network.

Another issue to contend with, in dealing with potential conflicts between GRUB (or LILO) and Windows MBR, is that Microsoft limits the number of installations of Windows XP to five times. I won't start trashing Microsoft, although I am tempted, but I cannot help but think of the contrast with Linux, which one can install repeatedly on the same machine or on multiple machines! :-)

Thank you again, Paul, for your insights. :-D

Cordially,

David

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