Do you have a separate boot partition?

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Do you have a separate boot partition?

Postby adrianHOOHAHA on Wed Apr 17, 2013 7:16 am

Do you need to have a separate /boot partition?

I do not have a firm grasp about how boot works. Since the first time I dual booted a linux with windows, I've been creating a separate /boot partition. I never tried overwriting GRUB to the MBR so I don't know how the actual booting process work.(the moment I press the power button)

Question 1:
For my laptop, when I press the power button, it will load BIOS then Windows Boot Manager next. then I can choose either win 8 or LM 14. when I choose LM 14, it will load GRUB then to the login page then to the desktop. is this the result of having a separate /boot partition -- having to load two bootloaders?

Question 2:
I just want to have one bootloader that can boot either win 8 or LM 14(either WIndows Boot Loader or GRUB). I use EasyBCD to put LM 14 as an option when Windows Boot Manager loads. and set GRUB timeout to zero. but I don't want to just hide it. I want it completely gone. the question is: do I not need to create a /boot partion during installation and just overwrite GRUB to the MBR? (as I'm considering to reinstall LM or wait for LM15 to come out) And will it make the boot process much simpler?
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Re: Do you have a separate boot partition?

Postby powerhouse on Wed Apr 17, 2013 5:41 pm

Do you have a separate boot partition? My answer is yes. But for totally different reasons. You don't need to have a separate /boot partition, but it can be helpful. I have it because my / root and /home partitions (actually all my partitions except /boot) are logical volumes (LVM). I use 1GB for the /boot partition, which should be plenty.

Nowadays booting has become a complicated issue: MBR, GPT, UEFI (EFI), you name it. You mentioned MBR, which is the simplest of all, though it has some restrictions.

A good place for info on booting and boot managers is here: http://forums.linuxmint.com/viewtopic.php?f=46&t=97221. Rod who opened that thread maintains/develops an UEFI boot manager called rEFInd. Windows 8 as well as Linux Mint 14 using kernel 3.5.x are able to directly boot via this boot manager. Have a look in the forum thread and on Rod's website - there is plenty of information on different boot options and of course on rEFInd.
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Re: Do you have a separate boot partition?

Postby pgmer6809 on Wed Apr 17, 2013 10:07 pm

Whether or not you have a separate Boot partition has nothing to do with how the boot manager works.
There is a requirement for GRUB that there BE a /boot directory, where it can find everything it needs to get the system running, but that can be a separate partition or just a directory under the root partition.

Can the Win8 boot manager boot a linux system? I don't know, I don't run win8, but I don't think so.

The BIOS (Actually the UEFI now since you have Win8, BIOS is gone) will run the Boot Manager.

Your disk should have a partition on it called EFI. (Fat32). UEFI is supposed to be able to browse this partition and find any bootloaders/boot managers that are there.
Do you have a partition of this type? does it have files (boot managers) ending in .efi for Win8 and Linux?

But UEFI is not smart enough to actually boot the OS on its own. It needs to run bootloader.
Today GRUB can be used as both a boot manager and a bootloader.
Grub can present a menu, (boot manager) and then when the user selects an entry it can do the necessary stuff to load and run the linux kernel (boot manager).
I THINK the latest release of GRUB can also load and run Windows8 (it can cetainly run earlier versions) but I am not positive.
So in theory you could have one and only one boot manager, and that boot manager would be GRUB.

But I advise against that. Microsoft don't want you to do that, so they make it very problematic.
And since the Win8 boot manager (probably) is not capable of booting linux, your best option seems to me to be what you have.
But if the Win8 boot manager CAN boot linux, then you could go with that.
------
There are lots of write ups on how the boot process works for linux. Fewer for Windows.
The MBR Linux boot works something like this:
BIOS runs. Loads about 440 bytes of code from the MBR. (This is called the IPL code).
IPL code loads about another 10-30KB of code from some known spot on the disk. (This would be GRUB for example).
GRUB loads extra code and menu etc from the /boot directory on the disk. (may or may not be separate partition)
User selects menu entry (or GRUB selects the default after a time out.)
GRUB then loads the linux kernel (eg vmlinuz) from the /boot area.
GRUB then loads the initial ram disk (initrd) from the /boot area.
GRUB then passes control to the kernel which uses the code in initrd to mount all the other disks it needs to get running.
The Kernel then starts the first process (init) which then runs all the other stuff including the desktop, the network, etc.

The UEFI process is similar except that since the UEFI can manage a FAT32 file system, it can load a boot manager in one step. (no IPL needed). So the UEFI can load GRUB (or the WIN8 Boot Manager) directly from the /EFI partition.
But I don't think UEFI is smart enough to load LINUX. It still is only smart enough to load GRUB.

One thing that boot managers can do is load each other (chainloader). So the Win8 boot manager can load the GRUB boot manager, and the GRUB boot manager can load the WIn 8 boot manager. That is how you are able to dual boot.
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Re: Do you have a separate boot partition?

Postby adrianHOOHAHA on Sun Apr 21, 2013 3:13 am

powerhouse wrote:Do you have a separate boot partition? My answer is yes. But for totally different reasons. You don't need to have a separate /boot partition, but it can be helpful. I have it because my / root and /home partitions (actually all my partitions except /boot) are logical volumes (LVM). I use 1GB for the /boot partition, which should be plenty.

Nowadays booting has become a complicated issue: MBR, GPT, UEFI (EFI), you name it. You mentioned MBR, which is the simplest of all, though it has some restrictions.

A good place for info on booting and boot managers is here: http://forums.linuxmint.com/viewtopic.php?f=46&t=97221. Rod who opened that thread maintains/develops an UEFI boot manager called rEFInd. Windows 8 as well as Linux Mint 14 using kernel 3.5.x are able to directly boot via this boot manager. Have a look in the forum thread and on Rod's website - there is plenty of information on different boot options and of course on rEFInd.


ok thanks for the link! :D and thank you for your time.

pgmer6809 wrote:Whether or not you have a separate Boot partition has nothing to do with how the boot manager works.
There is a requirement for GRUB that there BE a /boot directory, where it can find everything it needs to get the system running, but that can be a separate partition or just a directory under the root partition.

Can the Win8 boot manager boot a linux system? I don't know, I don't run win8, but I don't think so.

The BIOS (Actually the UEFI now since you have Win8, BIOS is gone) will run the Boot Manager.

Your disk should have a partition on it called EFI. (Fat32). UEFI is supposed to be able to browse this partition and find any bootloaders/boot managers that are there.
Do you have a partition of this type? does it have files (boot managers) ending in .efi for Win8 and Linux?

But UEFI is not smart enough to actually boot the OS on its own. It needs to run bootloader.
Today GRUB can be used as both a boot manager and a bootloader.
Grub can present a menu, (boot manager) and then when the user selects an entry it can do the necessary stuff to load and run the linux kernel (boot manager).
I THINK the latest release of GRUB can also load and run Windows8 (it can cetainly run earlier versions) but I am not positive.
So in theory you could have one and only one boot manager, and that boot manager would be GRUB.

But I advise against that. Microsoft don't want you to do that, so they make it very problematic.
And since the Win8 boot manager (probably) is not capable of booting linux, your best option seems to me to be what you have.
But if the Win8 boot manager CAN boot linux, then you could go with that.
------
There are lots of write ups on how the boot process works for linux. Fewer for Windows.
The MBR Linux boot works something like this:
BIOS runs. Loads about 440 bytes of code from the MBR. (This is called the IPL code).
IPL code loads about another 10-30KB of code from some known spot on the disk. (This would be GRUB for example).
GRUB loads extra code and menu etc from the /boot directory on the disk. (may or may not be separate partition)
User selects menu entry (or GRUB selects the default after a time out.)
GRUB then loads the linux kernel (eg vmlinuz) from the /boot area.
GRUB then loads the initial ram disk (initrd) from the /boot area.
GRUB then passes control to the kernel which uses the code in initrd to mount all the other disks it needs to get running.
The Kernel then starts the first process (init) which then runs all the other stuff including the desktop, the network, etc.

The UEFI process is similar except that since the UEFI can manage a FAT32 file system, it can load a boot manager in one step. (no IPL needed). So the UEFI can load GRUB (or the WIN8 Boot Manager) directly from the /EFI partition.
But I don't think UEFI is smart enough to load LINUX. It still is only smart enough to load GRUB.

One thing that boot managers can do is load each other (chainloader). So the Win8 boot manager can load the GRUB boot manager, and the GRUB boot manager can load the WIn 8 boot manager. That is how you are able to dual boot.
pgmer6809


oohh so it's my call if I want to place a /boot in a separate partition? then what about overwriting the MBR with GRUB? why do people do that?

my laptop comes with BIOS and with no OS pre-installed. I tried to search on google if my motherboard is UEFI-capable, but I can't find a solid answer. (My laptop by the way is a Lenovo IdeaPad Z470.)
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Re: Do you have a separate boot partition?

Postby powerhouse on Sun Apr 21, 2013 4:54 am

Since your laptop comes without OS, it's your decision whether or not you want to have a separate /boot partition.

About UEFI (or EFI): If your laptop supports regular MBR (legacy) boot, use that. UEFI is just complicating things. If you have reasons to use UEFI, follow the link(s) I posted. If you want to try LVM partitions and UEFI boot, see this little how-to I wrote: http://forums.linuxmint.com/viewtopic.php?f=46&t=107620#p608123.

About grub and MBR: When you install Linux Mint you will have to specify where to install the boot loader. At some time grub-install will write a MBR which contains both the partition table as well as some code to load grub and boot the system. See http://en.wikipedia.org/wiki/Master_boot_record for more on MBR.

When you boot your PC, the BIOS will load the MBR and execute the code. Since the MBR can't hold much code, the code that is placed in the MBR usually chain-loads another boot loader (grub) to boot the system.

If you only want to run Linux on the laptop, then just go ahead and install it. If you plan to run both Windows and Linux (dual-boot), then check out the advise on the forum concerning dual-boot. For example, my experience tells me to first install Windows, then make a backup, then install Linux. I've seen Windows wiping out Linux without even asking for confirmation by the user (I think this was with Windows XP?). But I'm no expert in Windows and dual-booting - I run my Windows as a virtual machine (VM).

About partitioning: For MBR type setups, I have the following partitions:
/boot ~ 1GB
swap - for laptops it's the size of the RAM or more. If you got 4GB, make the swap size 4GB. This way you'll be able to hibernate the laptop.
/ (root) ~ 15GB-20GB
/home - the rest of the drive

Having different partitions for / and /home allows you to install a newer version of Linux into / without touching /home and all your data. That way I was able to wipe out LM13 and install LM14 with all my user settings and data untouched and intact. Of course, I did do a backup of my /home partition before that, just in case.
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Re: Do you have a separate boot partition?

Postby adrianHOOHAHA on Sun Apr 21, 2013 10:01 am

powerhouse wrote:Since your laptop comes without OS, it's your decision whether or not you want to have a separate /boot partition.

About UEFI (or EFI): If your laptop supports regular MBR (legacy) boot, use that. UEFI is just complicating things. If you have reasons to use UEFI, follow the link(s) I posted. If you want to try LVM partitions and UEFI boot, see this little how-to I wrote: http://forums.linuxmint.com/viewtopic.php?f=46&t=107620#p608123.

About grub and MBR: When you install Linux Mint you will have to specify where to install the boot loader. At some time grub-install will write a MBR which contains both the partition table as well as some code to load grub and boot the system. See http://en.wikipedia.org/wiki/Master_boot_record for more on MBR.

When you boot your PC, the BIOS will load the MBR and execute the code. Since the MBR can't hold much code, the code that is placed in the MBR usually chain-loads another boot loader (grub) to boot the system.

If you only want to run Linux on the laptop, then just go ahead and install it. If you plan to run both Windows and Linux (dual-boot), then check out the advise on the forum concerning dual-boot. For example, my experience tells me to first install Windows, then make a backup, then install Linux. I've seen Windows wiping out Linux without even asking for confirmation by the user (I think this was with Windows XP?). But I'm no expert in Windows and dual-booting - I run my Windows as a virtual machine (VM).

About partitioning: For MBR type setups, I have the following partitions:
/boot ~ 1GB
swap - for laptops it's the size of the RAM or more. If you got 4GB, make the swap size 4GB. This way you'll be able to hibernate the laptop.
/ (root) ~ 15GB-20GB
/home - the rest of the drive

Having different partitions for / and /home allows you to install a newer version of Linux into / without touching /home and all your data. That way I was able to wipe out LM13 and install LM14 with all my user settings and data untouched and intact. Of course, I did do a backup of my /home partition before that, just in case.


"When you install Linux Mint you will have to specify where to install the boot loader" -- Its seems that I had completely forgotten about this stage. But I'm sure that I had it installed in the /boot partition.

anyway I have these partitions:
100MB system reserved
100GB windows C:/
500MB /boot
10GB /
2GB /home
and a 500GB storage

when dual booting, do you see a Windows Boot Manager after BIOS? or just GRUB?
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Re: Do you have a separate boot partition?

Postby powerhouse on Mon Apr 22, 2013 6:14 am

adrianHOOHAHA wrote:"When you install Linux Mint you will have to specify where to install the boot loader" -- Its seems that I had completely forgotten about this stage. But I'm sure that I had it installed in the /boot partition.


No, you haven't. It appears on the partitioning window, on the bottom - see below:

installation type.png



adrianHOOHAHA wrote:anyway I have these partitions:
100MB system reserved
100GB windows C:/
500MB /boot
10GB /
2GB /home
and a 500GB storage

when dual booting, do you see a Windows Boot Manager after BIOS? or just GRUB?


The partitions look fine. I can't answer your question as I'm booting into a Xen hypervisor with Linux Mint. But in the past I used to boot into the grub menu (with Windows XP). IIRC Windows 7 and 8 have their own boot manager, but I don't know how well they work with Linux. Do you have any problem with grub or the Windows boot manager?
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Re: Do you have a separate boot partition?

Postby adrianHOOHAHA on Mon Apr 22, 2013 6:58 am

powerhouse wrote:No, you haven't. It appears on the partitioning window, on the bottom - see below:

installation type.png


Now I remember! but I'm pretty sure that I selected the /boot partition(/dev/sda/***) on the drop down list.

powerhouse wrote:The partitions look fine. I can't answer your question as I'm booting into a Xen hypervisor with Linux Mint. But in the past I used to boot into the grub menu (with Windows XP). IIRC Windows 7 and 8 have their own boot manager, but I don't know how well they work with Linux. Do you have any problem with grub or the Windows boot manager?


I have no problems. It's just that I don't know how the whole booting process works but now I know how it works and how I want it to work. I will just run Windows Boot Manager by not installing grub to /dev/sda. I'll just install it to the / partition or a /boot partition and just set grub timeout to '0'.

thank you so much for answering my questions! I appreciate it. :D
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