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-   -   need help on /boot partition! (https://www.linuxquestions.org/questions/linux-newbie-8/need-help-on-boot-partition-651539/)

linbux 06-25-2008 07:55 AM

need help on /boot partition!
 
hi all
i want to install opensuse and fedora 9 in my PC.
i have a win xp pro too.
I've not any problem with dual boot (Linux and windows).

i want to know: is it a good idea to create a boot partition for my Linux installation?
and if it' good, should i create one boot partition for each Linux?
one for fedora and one for opensuse.
for example i have a 2gb swap partition and I'm using it for both Linuxes!

what size of boot partition is enough for me?
thanks all

PTrenholme 06-25-2008 08:18 AM

Assuming your boot loader is similar to the GRUB, you would probably be happier with a single boot directory shared by all your distributions. The main advantage of that arrangement is that you only have one boot configuration file that will need to be modified when any of the distributions change.

On the other hand, if you use your BIOS to select a boot location when you boot, then all distribution can be on different drives, with their own boot loader on that drive. The advantage of that arrangement is that each distribution is completely isolated from any other distribution. Thus each distribution can manage it's own loader without any possibility of changes in that distribution impinging on the loading of other distributions. Note, however, that this method does require that each distribution be on a different physical drive unless your BIOS can activate a specific partition as a "boot" partition "on the fly." That's because each distribution in this method is using a different boot loader.

linbux 06-25-2008 08:34 AM

really what is /boot partition? why we use it?

alan_ri 06-25-2008 08:42 AM

You don't need /boot partition and I wouldn't recommend that you create one.Install Fedora's or Suse's boot loader on the MBR and the other one on the root partition.Since you are having Window$ put Linux distros on the logical partitions and Window$ on the primary,otherwise you may run into the problems while trying to boot into the Window$.

yancek 06-25-2008 08:45 AM

Here's a link that describes what a boot partition is and reasons for using it. It is written specifically with Ubuntu in mind but the basic theory is the same for any distribution:

http://users.bigpond.net.au/hermanzo...boot_partition

If you have multiple distributions, you will need to edit the menu.lst file and place entries there so you can see them on boot. This file is in the /boot/grub directory. In Fedora, it is named grub.conf rather than menu.lst.

jiml8 06-25-2008 08:48 AM

If you use Fedora, you had better install a boot partition. Fedora's default installation will give you a virtual drive, and you can't boot from that. Once you set up one boot partition you can boot as many distros from it as you choose, if you use grub and proper configuration.

onebuck 06-25-2008 12:03 PM

Hi,
Quote:

Originally Posted by linbux (Post 3194645)
really what is /boot partition? why we use it?

The '/boot' is a directory that can be on a separate partition that would be mounted too the '/' filesystem. In earlier times when we had a cylinder limit of 1024 we would create a '/boot' partition within the 1024 limits. You can do a google/linux search and get a lot of information on the 1024 limit(s).

With modern computer systems and hdd subsystems we don't need to use the '/boot' on a separate partition.

masinick 06-25-2008 01:51 PM

Use /boot directory but not a separate boot partition
 
Quote:

Originally Posted by PTrenholme (Post 3194629)
Assuming your boot loader is similar to the GRUB, you would probably be happier with a single boot directory shared by all your distributions. The main advantage of that arrangement is that you only have one boot configuration file that will need to be modified when any of the distributions change.

On the other hand, if you use your BIOS to select a boot location when you boot, then all distribution can be on different drives, with their own boot loader on that drive. The advantage of that arrangement is that each distribution is completely isolated from any other distribution. Thus each distribution can manage it's own loader without any possibility of changes in that distribution impinging on the loading of other distributions. Note, however, that this method does require that each distribution be on a different physical drive unless your BIOS can activate a specific partition as a "boot" partition "on the fly." That's because each distribution in this method is using a different boot loader.

As Onebuck has explained, and I agree with him, /boot partitions are seldom necessary. I maintain that with GRUB, even if you should mess up, you can still get to any file system or partition that is addressible from GRUB. The challenge, then, is to get the GRUB entry correct. With UUID conventions, that is getting easier and easier. With SCSI identifiers it is also easy, but you can run into issues if the SCSI identifier of what you are installing is not configured on the system from which you intend to manage your boot loader. If you get stuck in that way, use the traditional Linux partition device name in your GRUB spec, for example /dev/sda5 or the older /dev/hda5 to refer to the fifth partition on the first disk.

What I try to do when I perform an installation is that I attempt to create a GRUB menu configuration for each system, but instead of installing it to the MBR, the Master Boot Record, instead I install it to the /boot/grub directory of each system I install. Then, once everything is installed, I go back to the system from which I want to manage GRUB, mount the file system of the system I recently installed, and copy the GRUB menu entry from that system to the one I am using to manage the MBR instance of GRUB. That works with one exception - if the GRUB entry has a SCSI disk ID for the location, it may have to be replaced by the device name or, if you can find it, the UUID. Then the scheme works properly.

This may all be confusing, though, so if there is anything that you do not understand, please ask.

Hope this helps and is not too confusing.

PTrenholme 06-26-2008 10:01 AM

The comments and references above should make it clear to you. Be sure that you understand the difference between a partition and a directory, and the difference between the directory organization on a Linux system and a Windows system. (Basically, that Linux uses a single file system, and Windows uses a separate file system for each partition.)

This may help you follow the advice offered by masinick:
Quote:

Originally Posted by masinick (Post 3194989)
<snip>That works with one exception - if the GRUB entry has a SCSI disk ID for the location, it may have to be replaced by the device name or, if you can find it, the UUID. Then the scheme works properly./snip>

Most kernels automatically create an entry in /dev called disk with several sub-directories at which you can look to find your UUID, etc. Here's an example from my Kubuntu laptop:
Code:

peter@HP-DV9810US:~$ ls /dev/disk
by-id  by-label  by-path  by-uuid
peter@HP-DV9810US:~$ ls -l /dev/disk/by-uuid
total 0
lrwxrwxrwx 1 root root 10 2008-06-25 22:07 17841f9e-fa3a-4850-aa52-0e6d0ba242e3 -> ../../sda5
lrwxrwxrwx 1 root root 10 2008-06-25 22:07 22b2553f-6199-4b82-b20c-6ad7c7b6688f -> ../../sda6
lrwxrwxrwx 1 root root 10 2008-06-25 22:07 2C88743C8874071C -> ../../sda2
lrwxrwxrwx 1 root root 10 2008-06-25 22:07 342D7D7923AC4107 -> ../../sda1
peter@HP-DV9810US:~$


mostlyharmless 06-26-2008 03:20 PM

If you want to use an encrypted root file system (probably a good idea for a laptop at least), a separate /boot partition will be necessary.

PTrenholme 06-26-2008 05:35 PM

Quote:

Originally Posted by mostlyharmless (Post 3196166)
If you want to use an encrypted root file system (probably a good idea for a laptop at least), a separate /boot partition will be necessary.

Not really. All you need to do is, e.g., encrypt /home and the children of /home or, if more than one person uses the system, encrypt each sub-directory of /home separately. Everything else on your system should be FOSS, and not worth protecting. (Well, perhaps /etc might contain something worth protecting, but you shouldn't need to protect your whole drive. :cool:)

mostlyharmless 06-27-2008 05:56 PM

True, though some consider whole partition encryption more secure than directory encryption. If you put /home on its own partition,then you might as well have done /boot. The point is, for partition level encryption, you need at least 2 partitions...but we're probably getting off the OP's topic.


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