How to install and boot 145 operating systems in a PC

Swarup,

Keep coming with the good words and I might just be able to persudae the Justlinux Admin to upgrade my company bicycle to a company Ferrari, even I haven't seen my company bicycle yet!

I am just a pupil here starting as an absolute beginner a few years back. Wait until you see my teachers and the village olders here. The big guns are among the members and the super moderators here. I am helping others in exactly the way I was helped. I just pray they are not disappointed me as a byproduct of the Justlinux forum.

The answer to your question should be yes but I have not done a full example recently.

You can shrink a partition on either to the left or to the right or even on both ends but you need to know the following

(1) It is best to do one shrink at a time.

(2) It is essential that you never shrink the partition that is providing the operating in use. Think about it and you will understand. No one will be please to return home to find it half the size. There is something to do with the integrity of the OS too. No decent OS would permit itself to be shrunk "while" operating. In other word use Linux A to shrink Linux B.

(3) Linux boot loaders, both Grub and Lilo, work by refering to the hard disk address of the partition, the form of which cylinder, head and sector. Once a partition has been shrunk the original hard disk address is void and so either Grub or Lilo will need to be restored. The Just Booting Tips Section B has all the details to do such restores.

(4) If you shrink a logical partition sda5 you only shrink its boundary inside the extended partition envelope sda2. The original extended partition envelope sda2 is not changed at all and so the vacant space will not be availbe to primary partition sda1 outside. To allow the outside primary partition sda1 to access the free space you need to shrink the extended partition as the second step.

Once the extended partition sda2 is shunk to remove the empty space the vacant area will be availble outside to permit the primary partition sda1 to expand its right hand side.

(5) Although it is slower I would recommend to do one step at a time and only resize Xp in sda1 after satisfying all your sda5 and sda6 are working normally.

Linux is nice to work with because you can know everything you are doing. In the majority of the cases you can even reason it out.

Quote:

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Originally Posted by saikee

Keep coming with the good words and I might just be able to persudae the Justlinux Admin to upgrade my company bicycle to a company Ferrari, even I haven't seen my company bicycle yet!

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I hope they give you the Ferrari soon. You're worth every bit of it! :)

A couple of follow-up questions:

1.

Quote:

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Originally Posted by saikee

(3) Linux boot loaders, both Grub and Lilo, work by refering to the hard disk address of the partition, the form of which cylinder, head and sector. Once a partition has been shrunk the original hard disk address is void and so either Grub or Lilo will need to be restored. The Just Booting Tips Section B has all the details to do such restores.

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I have done numerous shrinks from the RIGHT side of a partition in the past, and this never required me to restore Grub or Lilo in the past. Is it different somehow for the LEFT side?

2. Does it take longer to shrink from the LEFT side of a partition than from the RIGHT side, since (as I understand) there are some important sections of the partition and a lot of data on the "left" side that needs to be moved at the time of a shrink? Also, as a result of this increased need for moving data from the LEFT side compared with the RIGHT side, is it also more risky vis-a-vis possible partition damage or data loss, to do a shrink from the LEFT side as c/w the RIGHT side? Or is this all just misunderstanding of the issue from my side. Bottom line: is there ANY difference in doing a shrink from the LEFT versus the RIGHT-- and if so, then what is the difference?

Answers

(1) The 1st complete track of a Ext2/3, NTFS, Fat16 and Fat32 is the reserved boot sector where Grub or Lilo resides. Neither gives a toss to what happen to the end of the partition. If you do not restore the hard disk address Grub or Lilo simply goes back to the unshrunk partition location to find its system files and you will get a complaint from the boot loader.

(2) Don't really know the answer myself. Your explanation is as good as any. Don't think there is any risk in the software but if the reszing takes a long time to complete then your hardware has more chance to overheat and misbehaves. Thus I suppose shrinking the right boundary of a partition is less risky than the left boundary. However when you need space you simply shrink once and choose the convenient side to do it. Choose the right boundary to shrink first and then move the shrunk partition bodily to the right just to obtain space on the left boundary gains nothing in practice because the bodily movement probably takes longer.

Quote:

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Originally Posted by saikee

Answers

(1) The 1st complete track of a Ext2/3, NTFS, Fat16 and Fat32 is the reserved boot sector where Grub or Lilo resides. Neither gives a toss to what happen to the end of the partition. If you do not restore the hard disk address Grub or Lilo simply goes back to the unshrunk partition location to find its system files and you will get a complaint from the boot loader.

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Unless it is only a shrink from the LEFT and not from the RIGHT which requires restoration of the HD address, this does not seem to be required in my system. Perhaps Parted Magic uses such a technique which does the restoration of the HD address automatically. Because I have done quite a number of RIGHT side shrinks, and I have never restored the HD address, and nor have I ever gotten a complaint from the boot loader.

The righ hand side of a partition is its end! A boot loader always boots the beginning of the partition and so only the left boundary matters.

Good day!

Im a newbie to Linux. Is there a way to use this tutorial in installing multiboot Linux to USB HDD. Thnx in advance.

Xthink,

Welcome to Justlinux.

I believe this 18-month old thread may be the answer you are after.

Well done. This thread helps me understand more about multiboot and grub. Thx. :)

Quote:

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Originally Posted by saikee

Xthink,

Welcome to Justlinux.

I believe this 18-month old thread may be the answer you are after.

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Thank you very much for the link. Sorry if I don't see it before asking. This is a very informative forum. More power!

CNET had a weekly question on how to dual boot XP and Vista. I did not read all the nonsense, but I did skip through all 5 pages, and did an EDIT --> Find --> for "Grub" (no quotes) on each page with no results found. Gross!

I honestly think the booting problem is a M$ self made thing. In Linux this problem doesn't exist. The root of the problem of the M$ boot loaders is they have a huge difficulty to "chainload" their own systems.

Vista is one of the 5 M$ Windows I booted in this thread and one of the 145 systems I recorded here. It is in the partition hdc3 as indicated in the presented menu.lst.

What could be regarded as strange to some may be as far as Linux is concerned Vista can be booted exactly like any one of the 145 systems here when the thread was written nearly two years ago.

We can installed and boot 2 Vista without even install a Linux. Just 2 files from Grub are enough.

The booting of Xp and Vista can be made easy by any Linux and I wrote this thread just for the Newbies corner.

It is possible that M$ users are not conditioned to multi-boot. When they get a Vista boot loader BCDedit they may find it hard to put it into use. To a Linux guy I just put 2 and 2 to make 4 by using Vista's boot loader to boot 150 Linux. It was just a simple job of dabbling a Pyhton script.

Holy **** :-)

I am interested in using your technique to load multiple Live CDs onto individual partitions on a USB memory stick and use the simple GRUB chainloader to decide which to start. This would mostly be for demonstrating various Linux distros, and for troubleshooting and recovering borked computers. The keychain Swiss Army Knife for computers.

The challenge for me is in how to get the Live CDs installed into a partition so that it includes its own bootloader. The CDs normally uses isolinux. I need to change to extlinux when I copy the files to the USB stick partitions, then change the various file and directory names from isolinux to extlinux. It should work, but I am still having trouble getting the extlinux installation correct.

I am trying to install the Ubuntu Live CD into the fifth partition of my USB stick. I copied all the files, changed the names to extlinux, installed extlinux, set the boot flag on the partition in order to test it, but it doesn't boot. I just get "boot error".

Once I get it to boot correctly from its partition, I will change the boot flag back to the first partition where I have GRUB and boot it using the chainloader command.

On my 8Gb USB stick, I plan to use the first 2Gb for a data only (FAT) partition. I have Puppy Linux installed in the next partition, and it is working fine with the GRUB chainloader. The next partition is the System Rescue CD, and I can't get chainloader working yet. The next partition is the Ubuntu Live CD, and chainloader isn't working yet there either.

Since Puppy is an actual full install, it installed its own extlinux bootloader, so it worked fine. Since I am copying files from bootable CDs into the respective partitions for the next two, I have to manually get extlinux working on them. I seem to be missing something, probably related to the partition's boot sectors, but I'm still working on it.

Thanks for the great thread! I'm a Linux Newbie and learning a lot!

>>>> Clay >>>>

clayg,


Welcome to Justlinux.

Been two years since I wrote this thread.. I think it explains some of your problem. Haven't tried much on USB pen drive since because an external hard disk is much faster and easier for the same thing.

If you want the Linux to work as a Live CD just copy the files, after expanding them from the iso file by a loopback device, onto the USB and change the isolinux to Grub. The above thread gives several conversion examples. They are pretty straight forward.

Of course, grub would work fine, if I could figure out all the right parameters for each individual Live CD that I want to load. But I like your way of having a simple and consistent GRUB chainloader entry for every partition on the USB stick.

Last night I was successful in getting it to work. The tricky part is changing isolinux (which the Live CDs use to boot) into extlinux (which works on the USB stick) and also adding the mbr.bin to the boot block of each partition. That makes each Live CD bootable inside its own partition. Then the chainloader command works.

I have five partitions loaded and working so far and have only used about half of my 8Gb USB stick. You are right, an external hard drive is much bigger, better and faster for doing full disro installations. But they are not very convenient for carrying around on a keychain! By using the compressed read-only files from the Live CD, I can install several bootable environments and utility disks onto the USB stick and carry it around to do Linux demos (or installations!) or to use the various recovery tools (Ultimate Boot CD, System Recovery CD, etc.).

Thanks for the inspiration!

>>>> Clay >>>>

I've hit a snag in my project. I have an 8Gb USB memory stick and I have one FAT partition of 2GB for shared data and GRUB. Then I have multiple ext2 partitions for loading various Linux distro "Live CDs", utility disks, and some full installs of small distros. I want a fully bootable install of each in its own partition, so that I can use your chainloader scheme to start any of them from one GRUB menu.

The plan is working fine with Puppy Linux in Partition #2 and System Rescue CD in Partition #3. I converted the ISOLINUX from the Live CD to EXTLINUX on the USB partition. These two both work fine with the GRUB chainloader. It is after that where I run into trouble.

Partition #4 is the Extended partition that houses the Logical partitions, #5, #6, #7, #8, etc. When I use the same EXTLINUX method to load a Live CD (Ubuntu, for example) into one of these Logical partitions, it refuses to boot from the GRUB chainloader. I can put a full stanza into GRUB (title, root, kernel, initrd) and they will then boot up just fine. But when I try to use the chainloader, I just get a "Boot error" with no error code or other information.

The reason that I wanted to use the chainloader command is partly for consistency, and partly because on some Live CDs, I have not been able to figure out what to put into the full GRUB stanza to get it to boot correctly. Take Ultimate Boot CD for example, I can't find a description anywhere of what would go into a GRUB menu to start that CD.

It seems like the EXTLINUX should boot from the GRUB chainloader, but it is only working for me in the two Primary Partitions (#2 and #3), not in any of the Logical Partitions. Since you are clearly using the chainloader command to boot from many Logical Partitions on your hard disks, I was hoping that you might be able to give me a clue as to where to look for a solution on my USB stick drive.

Thanks,

I did not use Extlinux because with Grub I can boot everything manually and find out exactly which step doesn't work.

The author of Extlinux states this boot loader is "light weight". My feeling is if it is similar to syslinux, which boots mainly from a fat partition then it may have some limitations. Extlinux is different to syslinux by able to read an ext2/3 partition. In general a boot loader is a very small program not designed to read every filing system. Grub for example cannot read a NTFS partition. What Grub excels is it can chainload any installed system but that ability is not universal in every boot loader.

Many boot loaders are designed to boot only the primary partitions (the first 4 in a disk) because the code can be a lot simpler as the partition table is inisde the MBR which is only 512 bytes long. To boot a logical partition the hard disk has to be read several times because each logical partition carried the hard disk address of the next logical partition. When I recently putting Xp into 126 logical partition Grub suffered a big delay penalty because it had to spend a significant amount of time just to locate the correct partition.

The success of booting Linux off a USB drive also depends very much on how the distro has been put together. The access time in a USB device is a a lot slower and the kernel may not be able to find the correct system files in time during a boot up, as many files are loaded simultaneously. My point is success is not guaranteed as the case with an internal hard disk based on which the distros have been assembled.

Hello sir,
I use Ubuntu as my main OS and upon my recent upgrade to a larger hard drive have been multibooting Ubuntu 9.04 amd64 with Windows XP and Windows Vista 64-bit. Just today GRUB has started acting up (either not loading, hanging at a white flashing cursor, or waiting up to 3 minutes to load http://ubuntuforums.org/showthread.php?p=7758331 if you are interested). I am afraid I will have to reinstall GRUB.

Your post gives me some much needed confidence. I recognize that GRUB is both powerful and laughably simple but while there are many how-tos for common problems there are not any comprehensive but readable sets of documentation for non-developers who simply seek to better understand their system and the process of debugging it.

I write here to ask about your experience working with loading Vista from GRUB as I am somewhat nervous about reinstalling GRUB without making XP or Vista un-bootable. Currently my set up is

hd1,0 Dell Utility Partition
hd1,1 Windows XP Pro
hd1,2 Windows Vista Business 64 Bit
(I don't know if GRUB counts extended partitions if so add one number to subsequent partitions)
hd1,3 Empty partition for testing OSes
hd1,4 Linux swap
hd1,5 Ubuntu 9.04 amd64
hd1,6 Storage partition

Ubuntu works great and I am pretty comfortable with modifying how GRUB interacts with it. On the other hand for the Windows OSes GRUB points to hd1,1 (Windows XP), where it appears to store the Windows Boot Manager which can then boot into Vista or the XP. Although I suppose I could just leave it there and have the new installation of GRUB continue pointing to that I would kind of like to have GRUB load each OS individually.

Do you have any ideas on how I could remove the Windows Boot Manager but leave both XP and Vista bootable so GRUB could chainload them?

Thanks!

adempewolff,

I just came back from an overseas trip to post a late reply.

Grub counts from zero. Disk (hd1) is the second hard disk. If you have only one hard disk then it should be (hd0).

The first 4 partitions, from (hd0,0) to (hd0,3), are primaries. If you use logical partitions then one of them must be given up to form an extended partition. A hard disk can have only one extended partition which has no storage of its own. It simply acts as a boundary for a set of logical partitions inside. Any partition starting from (hd0,4) or the 5th position is a logical partition. I suggest you post the terminal output of

Code:

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sudo fdisk -l

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for us to see if you are not sure. The "sudo fdisk -l" is a Linux command with partitions listed in sda1, sda2 etc. You can get the equivalent in Grub by command

Code:

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sudo grub
geometry (hd0)
quit

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You cannot remove the boot manager of a MS Windows because it will not boot. The idea is Grub boots up a Windows boot loader, hands over the control to it and it is the Windows boot loader that actually boots up the MS system.

If you have two MS Windows of Xp and Vista then it is the Vista's bootmgr that controls both Windows because Xp must be booted by its boot loader NTLDR.

The actual working is Grub boots up bootmgr first when you select MS Windows. Inside it bootmgr gives you 2 choices of booting either Vista or Xp. If you choose Vista then bootmgr will fire it up. If you choose Xp then bootmgr will hand over the control to NTLDR which boots up the Xp. Since XP's NTLDR is older it can't boot Vista so the control must be by bootmgr of Vista only. In your case you will find bootmgr and NTLDR residing in the Xp partition. That is the normal way for the MS Windows systems. Both Vista and Xp store their boot loader inside the boot sector of their own partitions. There is no need to interfere with them.

Your information suggests Xp is at the front end so Vista during installation will have deposited its bootmgr in Xp's partition. All you need to do is to tell Grub to chainload that partition. The "sudo fdisk -l" should show up sda2 the Xp partition, by having type 7 for NTFS filing system and the partition being bootable (with a *).

Both Xp and Vista will have their boot loaders residing in the boot sector of their partitions. All you need is to chainload the partition that has bootmgr inside. My guess is these lines should fire up the bootmgr in the Xp partition

Code:

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title Xp partition assumed in (hd0,1)
root (hd0,1)
chainloader +1

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You can restore Grub by any Linux Live CD and the Ubuntu CD can be used for that purpose. Post the "sudo fdisk -l" and we can show you the steps.

Thanks for your reply. GRUB ceased acting up after several more reboots. It might have even been the BIOS, who knows. So I do not have an urgent need to reinstall GRUB anymore but I would still like to reconfigure how my computer boots. I also found your thread "Just Booting Tips" which was very informative and answered most of my questions about GRUB.

As soon as I submitted that post I realized it should be hd0 not hd1... oops.

What I was wondering if you had any idea how to do would be to configure xp and vista so they boot independently of eachother. Aka XP boots via NTLDR on its partition (hd0,1 or sda2) and Vista boots via the Windows Boot Manager on its partition (hd0,2 or sda3). The reason I would like to do it this way is because I may want to uninstall one of them in the future and I'd rather not have them dependent on eachother (or eachother's partitions) for booting.

I think I know how I would point to these in GRUB:

Code:

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title Windows XP
root (hd0,1)
chainloader +1

title Windows Vista 64
root )hd0,2)
chainloader +1

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But I don't know how to configure the windows OSes so that they will boot off their own partitions. So I do not want to remove the windows boot manager but rather move the Vista Boot manager to the Vista partition and then use the native NTLDR to load XP. I think that I might be able to do this by using the windows recovery console and using the commands "fixmbr" and "fixboot" and then reinstalling GRUB and reconfiguring it. I'm not confident that this would work though so I was wondering if anyone had any expirence. Hopefully I am more clear now about what I am curious about.

I don't think you need this anymore but just in case it better helps you visualize my setup:

Code:

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Disk /dev/sda: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00014c2c

  Device Boot      Start        End      Blocks  Id  System
/dev/sda1              1          3      24066  de  Dell Utility
/dev/sda2  *          4        5225    41945715    7  HPFS/NTFS
/dev/sda3            5226        9141    31455270    7  HPFS/NTFS
/dev/sda4            9142      30401  170770950    5  Extended
/dev/sda5            9142      10446    10482381  83  Linux
/dev/sda6          10447      10968    4192933+  82  Linux swap / Solaris
/dev/sda7          10969      13579    20972826  83  Linux
/dev/sda8          13580      30401  135122683+  7  HPFS/NTFS

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Thanks!

What you have asked is totally reasonable but incompatible with M$ arrangement.

I have successfully broken off the combined booting process of Xp/Win2k and Vista/Win7 but haven't written about it.

The Xp can be easily fixed. The fixmbr will restore the Xp's own version of MBR in the first sector of the first boot disk. That MBR boots the booting code inside the Xp partition's boot sector. Unfortunately M$ saw fit to use a different boot code for the Vista/Win7 and so your sda2 or (hd0,1) has the boot code from the bootmgr and not from the NTLDR.

By running the recovery console of a XP installation disc the command "fixboot" will restore the Xp boot code inside the Xp partition, by overwriting the Vista/Win7 version currently there. This will make the Vista unbootable.

Moving the bootmgr and the associated files from Xp partition sda2 to Vista partition sda3 does not help because bootmgr configuration file is now in binary and a relocation must be followed by an update. The best way is to hide the Xp partition and run the Vista installation DVD. In place of the Recovery Console Vista's equivalent is Command Prompt. You can run the program BCDedit.exe to restore the Vista's boot code and MBR this way. I believe between bootrec.exe or bootsect.exe you can achieve the same thing. Also the third party software like EasyBCD can also be used if you have another bootable Vista or Win7 partition to run it. Just type "bcdedit.exe /?" to get help and find out the parameters you can use.

Your current Vista cannot be booted by Grub as per your instruction in Post #140. Your Vista must be booted via the Xp partition in sda2. bootmgr will dual boot Xp and Vista there. That is how the M$ systems have arranged themselves. Unless you hide Xp otherwise Vista will mount it regardless. Therefore for multiple MS Windows you need only one boot loader, usually the latest, to control all the M$ systems. The only deviation is to hide every MS system and unhide the one you wish to boot.

If your Ubuntu is in sda7 then boot up a Ubuntu CD and use the terminal to restore Grub by these lines

Code:

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sudo grub
root (hd0,6)
setup (hd0)
quit
reboot

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The above commands Grub to "source" the Grub from 7th partition of the 1st disk and set up Grub in the MBR of the 1st disk.

Ah thank you for your informative and quick reply, it has answered all my questions--even if they weren't the answers I was hoping for.

I was hoping that I would just have to hide xp during the vista installation to keep them seperate but if I would need to keep it hidden except for when I booted into it, that solution is probably too complex (Unless GRUB had the capability to edit the partition type in the partition table as part of the chainloading process).

For now I guess I will just keep the boot manager and if I ever decided to remove Vista I will repair the XP partition by using fixmbr, followed by fixboot, followed by reinstalling GRUB from a live cd.

Thank you again for sharing your wisdom!

Actually Grub is tailor-made to hide and unhide partitions. Such capability is inside Linux's other boot loader Lilo too.

I have written this thread to show how to use Grub to boot two Vista. The procedure is identical to your case of booting Xp and Vista.

The typical Grub commands are listed here

Code:

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title 1st Vista in hda1
root (hd0,0)
makeactive
unhide (hd0,0)
chainloader +1

title 2st Vista in hda2
root (hd0,1)
makeactive
unhide (hd0,1)
hide (hd0,0)
chainloader +1

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The above method does preserve each MS boot loader in each MS Windows partition but the disadvantage is that you can access only one MS partition at any one time. By going with MS own method, which places all the required boot loaders in the first MS-recognised partition and mounts all partitions recognised by Windows, you can access all of them at the same time. The downside is if the booting partition goes down you have a big job to make the rest of the MS systems bootable again.

MS boot loaders are clumsy relative to Grub because MS does not want to support other systems except their own. Thus extra levels of complication are introduced to protect its commercial interest.

I have dabbled Vista/Win7's BCDedit.exe, bootsect.exe and bootrec.exe to find my way round. However to write something useful, to highlight the differece from NTLDR and to guide others to use them sensibly is a big investment of one's time.

When working with MS boot loaders I find that I need to spend three times more effort to get one-third of the work achieved with Grub.

Great tutorial, cant wait to test it out. By the way, can i boot MAC OS X with grub using this guide?

Reg777,

Welcome to Justlinux!

Never have a Mac myself so couldn't tell. However if it is a Linux implementation then it should work the same.

First of all, I am so glad that i stumbled upon your posts Saikee. I have become an instant fan of your posts and you are a celebrity in my world. Your instructions are clear and precise. I am pretty new to linux but am so deeply in love with it that I am posting this at 4:30am in the morning... lol... I go crazy about linux...

Anyhow, the problem:

I wish to create a bootable USB flash drive with dual/triple boot with various small distros such as DSL, Knoppix, INSERT.

So I took a 512MB Kingston SD Card, shoved it in a USB card reader and deleted whatever partition was there by default.

Using fdisk, i created two primary partitions for now. The first partition (sdb1), 10MB in size is FAT16, the second partition (sdb2), 60MB in size (for DSL) is ext3. The remaining space is empty for now.

I love your scheme of installing grub into it's own partition, hence I made the Fat16 partition.
I created /boot/grub dir structure in /dev/sdb1 and copied all the files from /usr/share/grub/i386-redhat/ into /boot/grub/

Then on my Centos system, I typed:
grub
root (hd1,0)
setup (hd1)
quit

Now, when I plug this USB into my thinkpad and boot from USB, I get the grub prompt. So far it's all good.

Next, I copy the 'boot' dir and 'KNOPPIX' dir that reside inside the dsl-4.4.10.iso image into /dev/sdb2 (the 60MB ext3 partition).

On /dev/sdb1, i create a menu.lst under /boot/grub/ and type this inside this file:
title Damn Small Linux
root (hd1,1)
chainloader +1

Save, exit, plug this USB into thinkpad and boot from USB, i still get the grub prompt. Shouldn't it show me the menu, or since there is only one item in menu.lst, boot directly into DSL. What am I doing wrong?

Thanks a lot in advance.

P.S. My Linux System is a Centos 5.2 running as a Virtual Machine on XP Host (VMware Workstation). Intel Core 2 Duo E8400, 4GB RAM.

Quote:

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Originally Posted by saikee

clayg,


Welcome to Justlinux.

Been two years since I wrote this thread.. I think it explains some of your problem. Haven't tried much on USB pen drive since because an external hard disk is much faster and easier for the same thing.

If you want the Linux to work as a Live CD just copy the files, after expanding them from the iso file by a loopback device, onto the USB and change the isolinux to Grub. The above thread gives several conversion examples. They are pretty straight forward.

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Hi, I just read posts by clayg and your response to it. You said to convert isolinux bootloader to grub. Why so? Can't grub just chainload isolinux and then isolinux can take charge of booting the distro? After all, chainloading means giving another bootloader charge for booting the OS.

The DSL that I copied to my partition also has isolinux as its bootloader.

crazy4nix,

Welcome to JustLinux!

isolinux is a boot loader for CD/DVD based on the iso9660 filing specification.

Grub is a boot loader based on block devices (like hard disk, USB pen drives) although it is also suitable for floppies.

Grub uses a different form of boot loader on a CD or DVD. Nornal Grub, now called Grub1 or Legacy Grub as Grub2 has been out, comprises of stage1 and stage2. A single stage2 called stage2_eltorito is used specifically for the CD/DVD structures.

stage2_eltorito does not boot a hdd or a floppy. A CD/DVD does not have a MBR and hence no stage1 application.

The author of isolinux wrote a separate boot loader for bock devices and floppies. It is called syslinux and is offered as a "lightweight" boot loader. It is quite popular with pen drives because I believe it is a Dos based program naturally fits in with the Fat16 and Fat32 filing format of the USB devices.

Hope the above is clear.

For the other post I am not sure exactly what you have done. Hence I can only offer a few pointers

(1) If you intend to boot the USB pen drive as the first booting device then it will be (hd0) to Grub but may be looked upon as sdb by CentOS.

(2) If your men.lst in sdb1 has been included to boot DSL then the Grub menu should show it even if it isn't bootable. Thus you may not have booted up the Grub in sdb1 of the USB drive. That is my currnet prediction according to the information supplied.

(3) You will not be able to boot DSL the way you had described. The "chainloader +1" can only be applied to the partition with a boot loader installed in its boot sector. It is known as an indirect method with which the Grub in MBR boots the boot loader in the partition specified by the "root" command. You have just copied part of the iso file and so no boot loader has been installed in sdb2. The way you described you are better off booting the DSL "directly" . This thread may be of interest to you. The thread was written for putting several Linux iso on a DVD but has been extended for USB devices.

If you like multi-boot then you have come to the right place. I am just a pupil from the masters here!

Thanks for your input.

(1) If you intend to boot the USB pen drive as the first booting device then it will be (hd0) to Grub but may be looked upon as sdb by CentOS.

Yes, when I plug my pen drive into my laptop and boot from it, it is hd0. (hd0,0) is a fat16 partition where i have /boot/grub/ and all the grub files in it.
(hd0,1) is a ext3 partition where i have copied the contents of dsl iso image, namely the directories 'boot' and 'KNOPPIX'


Now, in (hd0,0) I have /boot/grub/menu.lst with the following entry:

title Damn Small Linux
root (hd0, 1)
kernel /boot/isolinux/linux24 ramdisk_size=100000 init=/etc/init lang=us apm=power-off vga=791 nomce noapic quiet BOOT_IMAGE=knoppix
initrd /boot/isolinux/minirt24.gz

Note: In (hd0,1) I do have the following:
/boot/isolinux/linux24
/boot/isolinux/minirt24.gz



(2) If your men.lst in sdb1 has been included to boot DSL then the Grub menu should show it even if it isn't bootable. Thus you may not have booted up the Grub in sdb1 of the USB drive.

When I boot from my pendrive, i do get the grub prompt. That means that stage 1 grub in the mbr of (hd0) is calling the stage 2 grub in (hd0,0) and hence the grub prompt. Am i right? In other words, my stage 1 grub in the MBR is hard-coded to the grub in (hd0,0).



(3) You will not be able to boot DSL the way you had described. The "chainloader +1" can only be applied to the partition with a boot loader installed in its boot sector. It is known as an indirect method with which the Grub in MBR boots the boot loader in the partition specified by the "root" command. You have just copied part of the iso file and so no boot loader has been installed in sdb2. The way you described you are better off booting the DSL "directly" .

Yes, I understand now that I do NOT have the grub boot loader installed in (hd0,1), because I merely copied the contents of the dsl iso, and did not install it.
But, this time, if you look at my menu.lst in (hd0,0), I am calling the DSL directly. It should work this time, but it isn't.

I looked at your post titled "How to boot several CD iso files in a DVD" available at http://www.justlinux.com/forum/showthread.php?t=150078 but there, you have grub and all the iso's in the same partition. Here, I am trying to employ you strategy where the grub is on its own separate partition.
Please point my errors. Thanks a lot in advance.

Grub will default to a Grub prompt if a menu.lst could not be found in either /boot or /boot/grub directories. If the menu.lst is good Grub will execute it.

In your current case with a Grub prompt you can boot the system manually as follow

Code:

---

root (hd0, 1)
kernel /boot/isolinux/linux24 ramdisk_size=100000 init=/etc/init lang=us apm=power-off vga=791 nomce noapic quiet BOOT_IMAGE=knoppix
initrd /boot/isolinux/minirt24.gz
boot

---

The instructions are identical to what you claimed in the menu.lst except I omit the "title" statement and add the "boot" as a green light for Grub to proceed. That is standard way to boot any Linux manually by using just the instruction in menu.lst.

Booting the Linux manually is to ask Grub to tell you which line it doesn't like. You use Grub as your teacher.

You can also ask Grub to display the content of the menu.lst at a Grub prompt

Code:

---

root (hd0,0)
cat /boot/grub/menu.lst

---

and ask it to fire up this menu by

Code:

---

root (hd0,0)
configfile /boot/grub/menu.lst

---

Thanks for your help. I can now manually boot DSL Live from (hd0,1) and I also setup GParted Live in (hd0,2) and can also boot that from the grub prompt.

I wanted some clarification. The grub prompt is a courtesy of stage1 or stage2? If I don't have Stage2 on any partition, just stage1 in the mbr, will I get the grub prompt?

Secondly, even though I do have a /boot/grub/menu.lst together with all other grub files in (hd0,0) (the grub only data-partition), why am I not being shown the menu? Why only the prompt?

Thanks for all your time and help!

The stage1 is the part in the MBR. Without stage2 Grub cannot function at all. Since /boot/grub has stage2 therefore stage1 can be hard-coded to boot that file because Grub can read a ext2/3 partition. If Grub is avialable in the root partition of Linux then Grub can boot its boot sector directly by chainloading. The commands
[code]root (hd0,0)
chainloader +1
boot[/code[
liertally instruct Grub that the root of the system is (hd0,0) where the stage2 and menu.lst can be found. Grub is then asked to sever everything except its 1st sector in the memory and paste into the memory with the +1 position of the boot loader inside boot sector of partition (hd0,). The +1 position is the 2nd sector. That is why I always say Grub is laughingly simple and makes use of the key features of the Legacy partition table better than any other boot loader.

I have suggested to you to use "configfile" to boot the menu.lst. Does this work? If it works then it proves your menu.lst is executable by Grub. If you still get a Grub prompt then may be you set it up incorrectly, say by putting Grub from sda2 or (hd0,1). You can restore the Grub from (hd0,0) again in a Grub prompt

Code:

---

root (hd0,0)
setup (hd0)

---

and then fire it up immediately by

Code:

---

chainloader +1
boot

---

hi, sorry for the delayed response...
yes, i can now boot my distros using the following command:

root (hd0,1)
configfile /boot/grub/menu.lst

root (hd0,2)
configfile /boot/grub/menu.lst

Thanks for all your help. Appreciate it :)

we link to this thread often in emails and on forums!

thanks!

.

thank you for this howto, saikee. it has really helped, but still confused over a simple part.

I'm confused about the first two posts, in that grub boots from /dev/hda3, but the boot flag is set to /dev/hda1. How does the computer boot to grub first if boot flag is to /dev/sda1?

Also, is it correct that you did not install grub in /dev/sda1 or /dev/sda2 because of the 2GB limitations of Dos and Win3.1?

maek3rcr129 ,

Welcome to JustLinux!

The answer to your questions are

(1) Only the MS systems (Dos and Windows), Solaris and BSD systems boot loaders use the booting flag. Linux's Lilo and Grub never use it. Typically a MS systems stage1 boot loader (it doesn't have a name) searches the 4 primaries in the partition table and boot whichever one that has the booting flag switched on. We can place Grub inside a Fat partition, set it bootable and use Xp, Vista or Win7 boot loader to boot up Grub. I have demonstrated it in this thread.

(2) My thread was written when Linux still called the IDE disks as hda, hdb, hdc and hdd whereas sda, sdb etc were reserved for Sata disks or USB devices. Later kernels now call all disks sda, sdb, sdc etc. I placed Grub in hda3 as a data only partition. Each of all other partitions has an operating system inside and also its own boot loader.

It is an extreme case to demonstrate that Grub can be anywhere and can exist without an operating system attached.

If I put Grub inside say Dos or Win3.1 then I can't boot that system because the boot sector would be taken over by Grub.

In a normal case one can use a Grub from any of the Linux to do the same job. However I thought Linux users may like to know some powerful features of Grub.

Wow! I can't believe I never stumbled upon your amazing guide before now! I also boot dozens of distros, and your info gave me several "why didn't I think of that?" moments.

One question regarding the 16 partitions per drive issue... could you explain this to me? I have sometimes been able to create such partitions, but then whatever distro I was trying to install refused to use it. Btw, I have just 2 drives one internal SATA and one USB external SATA.

Thanks again for all your efforts!

claudecat,

Welcome to JustLinux!

The 16 partitions should be thought of 16 device names.

It has been long established, when we still started using Sata hard disks, tha total of 256 devices in the hard disk controllers. The kernel has long been written to permit 16 devices names per IDE/Sata/SCSI/USB hard disk. Since sda the whole hard disk is also a device name there effectively we can only have 15 partitions. Also one of the primaries must be converted to an extended partition and cannot store data therefore a hard disk has only 14 bootable partitions.

The partitioning tools between Gparted, fdisk, cfdisk, sfdisk, parted, etc, etc maintained to different vigor and while one allow more than 16 device names other may not.

Theoretically kernel newer than 2.6.28 should have no limitation on the number of partitions! However the various programs have not been revised to catch up with the changes in the kernel. More details in this thread

Another complication is the kernel can be newer than 2.6.28 and the partitioning tools are ready to exceed 16 device names but the distro's installer may not have been written to go beyond the 15th partition. This is the most common irritation.

The problem can be resolved tempoarary if you are willing to install the distro in one of the first 15 partitions and then move it to a higher partition. This is how I deal with them and most distros with new kernels will have no problem with the relocation.

Personally I believe Linux is ready to be installed into high number partition as Grub has no problem of booting it. The problem is with the partitioning tools because we still need them to be robust for sorting partition table if something goes south.

The partitioning tool that is currently able to create most number of partitions is one of the oldest "sfdisk". The graphic Gparted is pretty good too but one can write a script to create 130 partitions in seconds with sfdisk , as I demonstrate in this thread.

In general I would recommend sticking with cfdisk as the partitioning tool. It supports 64 device names so 63 partitions is the maximum. I would also limit the number of partition to a lower threshold of 60 because any space/gap between partitions (forced upon by the BSD/Solaris distros and MS Windows) attracts an allocation of device name.

Thanks for the welcome and the information. Plenty of ideas for future learning/projects. You are one amazingly grub/partitioning knowledeable human :=}

Hello saikee,

i have read the most of the postings in this thread but found no solution for my problem with Linux Mint 8...

My USB disk structure is:

Code:

---

Device      Part.Type  Format  Label  Marks
/dev/sdc1  primary    fat32    boot    boot
/dev/sdc2  extended
/dev/sdc5  logical    linux-swap
/dev/sdc6  logical    ext2    Dream
/dev/sdc7  logical    ext2    Arcade
/dev/sdc8  logical    ext2    Mint
/dev/sdc9  logical    ext2    Sabyon
/dev/sdc3  primary    fat32    HOME

---

First i installed DreamLinux 3.5 Gnome in /dev/sdc6 with grub in MBR and via terminal in /dev/sdc6 and copied the boot folder from /dev/sdc6 to /dev/sdc1.

Seccond i installed Linux Mint 8 Helena and its grub in /dev/sdc8.

The menu.lst on /dev/sdc1:

Code:

---

color red/black red/light-gray

title This is the frequently use Linux booting menu

boot
title DreamLinux @ sda6
root (hd0,5)
chainloader +1

title Puppeee Arcade @ sda7
root (hd0,6)
chainloader +1

title Linux Mint @ sda8 via chainloader
root (hd0,7)
chainloader +1

title Linux Mint @ sda8 via core.img
root (hd0,7)
kernel /boot/grub/core.img
savedefault
boot

title Sabayon Linux @ sda9
root (hd0,8)
chainloader +1

---

If i select DreamLinux it boots the DreamLinux menu and from there it boots DL like it should.

If i select "Linux Mint @ sda8 via chainloader" grub tells me:

Code:

---

Error 13: Ivalid or unsupported executable format

Press any key to continue...

---

If i select "Linux Mint @ sda8 via core.img" grub tells me:

Code:

---

, bss=0x0
Error 15: File not found

Press any key to continue...

---

Linux Mint 8 Helena uses /boot/grub/grub.cfg as boot meu seems it uses grub2...
Can you help me?



Greetings from Germany
Luemmel