Visit Jeremy's Blog.
Go Back > Forums > Linux Forums > Linux - Distributions > Red Hat
User Name
Red Hat This forum is for the discussion of Red Hat Linux.


  Search this Thread
Old 01-14-2005, 12:33 PM   #1
LQ Newbie
Registered: Jan 2005
Distribution: redhat 9.0
Posts: 3

Rep: Reputation: 0
Combining hard drives from separate redhat 9.0 installs

New to Please bear with me if this is the wrong forum!

The simple question is: How do you combine hard drives that have separate linux (+ windows 98) installations into a single machine, _and_ control which installation to use under grub. (I cannot afford to loose data, and can't remember which third-party programs have been installed.)

I installed a Linux Redhat 9.0 on two separate (physical) disk drives. Each disk drive was the only drive in (different) machines during the installation process. For each, grub (O/sys loader) was installed to load windows 98 as well. (The problem is the same with 3 drives or different versions of 2 or more Linux O/S's.) I can successfully use either drive on a given machine with no problems.

I now mount both drives on the same machine, and expect grub on the primary drive to load its O/S. Unfortunately, it looks like grub attempts to load the linux O/S's on both drives at the same time! It complains of duplicate boot, label, and/or does not find or could not write in certain partitions. Unfortunately, I cannot make sense of the messages in /var/log/messages. The entries for December 18 2004 (when I tried installing both disks on my machine in a systematic fashion) seems to large to attach and I'm not sure which bits to delete; will send if needed.

I have gone into linux rescue mode (and even emergency mode) on a *different* machine with similar problems and have also ran

# grub-install --recheck /dev/hda

as is recommended whenever you add a new drive, but to no avail.
Old 01-17-2005, 08:00 AM   #2
LQ Addict
Registered: Oct 2003
Location: Australia
Distribution: MX 16
Posts: 5,283

Rep: Reputation: Disabled
well in my howto I never recommend that way as it does not give any feedback

after if you care to ie read my howto and don't understand it

we need how each drive is installed
eg ide jumper master controller 1
cd jumper slave controller 1

then what each drive is

and if you have a knoppic cd or a rescue cd.....the output of all /etc/fstab files for each linux
and for each drive that has MS what partitions they are on

let us know if you have raided any as well and describe drives as IDE or scsi or sata plse

then what is your bios preferred boot order.....which mbr do you want grub to be was it in in it in the past etc

not too much detail is it? heh heh
Old 01-24-2005, 03:16 PM   #3
LQ Newbie
Registered: Jan 2005
Distribution: redhat 9.0
Posts: 3

Original Poster
Rep: Reputation: 0
The questions posed by aus9 helped me very much to formulate the correct hypotheses to solve the problem. Thanks! I also found the GRUB HOWTO and troubleshooter (thread id: 237511) very helpful. Below, I give feedback and end with some questions raised from the experience. (I am still working on another set of drives with similar problems.)

The problem got sorted once I grasped some of the subtleties of grub syntax from the howto guide. e.g.,:
- single space was important between *all* arguments.
- that <Esc> to main menu (at boot time) aborted commands that I thought were executed.

I found out that my problem with booting the linux installs on my hard drives was that the /etc/fstab file used the LABEL directive rather than the devices themselves (e.g., LABEL=/boot instead of /dev/hda1). Since similar partitions had the same label on both hard drives, partitions holding directories for separate installs were mixed! Things got looked for in the wrong place. Also, from the duplicate labels, the system tried to mount the labelled partitions more than once!

This was discovered when I looked at the partitions (via df) under linux rescue and discovered a mixture of partitions from different drives! I thus changed the fstab to have the device names directly.

Unfortunately, one looses the flexibility of changing drive partitions without changing fstab. (relabelling with e2label (8) will not do.)

1) I wonder if there is a known order for reading the partitions at boot time. In which case, one can arange to read in the correct partitions.

2) Also, is there a way of changing the labels so that they do not clash. Alternatively, how could one ignore duplicate labels?.

3) Is there some way newbies can more easily identify helpful threads like the one shown me. (FAQ and the search facilities were not that helpful in my case) One is overwelmed with information and following threads by number (e.g., 123456) over slow, unstable lines can be quite daunting!

4) Can grub permit one to have multiple passwords on a single menu item? (The password only allows for one!) This may be by finding out if a given password can be found in a file of passwords that may be encrytped or not! (I am trying hard to flip over to linux and I want only those who must use Windows to have access to windows partitions. Sharing passwords has proven ineffective.)

Thanks to all.

Old 01-25-2005, 02:50 AM   #4
LQ Addict
Registered: Oct 2003
Location: Australia
Distribution: MX 16
Posts: 5,283

Rep: Reputation: Disabled
you can probably guess I do not approve of RH or FC use of labels but if you like them instead of grub way
root=/dev/hda3 its root=LABEL=/label name.

2) bootloader password is only avail for one.......I think U have the wrong end of the stick.....if you are concerned with what people are doing with your personal computer......a bios password is safer.

3) but since you ask questions and I once had this in the howto....I will tell U a secret....just between me and 1500000 members ie.

create a menu.lst item that has NOTHING in the title when you want to boot it press the arrow down key to select it.

you can have many of these hiddden titltes, heh heh. when you arrow down to the last visible entry (title) start counting from there.......arrow downs are of course start from one not zero heh heh


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Dual boot with 2 separate hard drives and OS lfierro Linux - Newbie 8 12-11-2004 02:37 PM
Dual Booting, 2 separate hard drives Jotun Linux - Newbie 6 04-30-2004 12:18 PM
Dual Boot on Separate Hard Drives? theonlylivinggo Linux - Newbie 6 02-26-2004 04:15 PM
dual boot w/ separate hard drives? aveach Linux - General 2 09-15-2003 03:33 PM
Dual-booting with two separate hard drives leeman_s Linux - General 3 01-22-2003 11:16 PM > Forums > Linux Forums > Linux - Distributions > Red Hat

All times are GMT -5. The time now is 06:12 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration