sharing /boot. Good or Bad idea?

kcy29581 · 2005-07-07 19:21:43

Hi all,

If I want to install 2 distributions on one drive, I know I can share the swap partition. What about the /boot partition? My personal view so far, is that sharing a /boot partition is a bad idea, as overwritting can occur.

Any ideas/solutions on this? I understand that the bootloader must be installed only once (duh!) and that it should be configured to contain the 2 entries. My main concern is just how safe sharing /boot is?

Thanks

Dusty · 2005-07-07 19:26:05

Its considered a good idea, because you can then have all your kernels in one place. It kind of sucks having to copy them between partitions when you want to install a new OS.

However, I personally don't like doing it as I've been stung with overwritten kernels before. I'd suggest not putting it on a separate partition.

Dusty

i3839 · 2005-07-07 19:32:15

I'm using /mnt/boot instead and normally keeping it unmounted, that way I'm sure it isn't tinkered with behind my back.

phrakture · 2005-07-07 19:44:46

i3839 wrote:

I'm using /mnt/boot instead and normally keeping it unmounted, that way I'm sure it isn't tinkered with behind my back.

I actually don't mount my /boot part (noauto) at all unless it's needed

i3839 · 2005-07-07 20:11:48

Yes, but having /boot looked ugly to me, so I moved it away. I moved /root to /home/root too...

vacant · 2005-07-07 20:38:49

My PC is far to volatile to trust a single /boot.

I run Arch, I run Mepis, I then have another partition where I install whatever distro I'm playing with. One day I just know if I had a separate /boot and actually let the play distros know about it, one of them would decide it had better format the partition before planting it's kernel there

kcy29581 · 2005-07-07 21:45:33

Thanks for all the replies guys. I think the best thing is to keep everything separate as well, after reading up more on this.

If I already have:

/boot
swap
/

partitions (in that order on the disk) for Arch, say, and I wanted to install Suse 9.3. I was thinking of shrinking the / partition, and at the "end" of the disk install Suse on it's own / partition, without actually making an extra separate /boot partition.

Is that wise, or am I speaking crap? :?

i3839 · 2005-07-07 22:11:34

It's what I did when installing Arch...

Dusty · 2005-07-07 22:28:08

I don't have a /boot partition at all; my /boot folder is on the root (/) partition. That's an option too.

Dusty

kcy29581 · 2005-07-07 23:09:15

right.

@Dusty:

The reason I always have a /boot partition is because of 2 reasons:

1) make sure /boot is bootable
2) security by having it not mounting automatically

I think today bootability (if thats a word...) is not an issue: the /boot partition doesn't have to be at the beginning of the drive anymore to boot. So I guess security is the main reason, nothing else, and I'm not too bothered by that.

So Dusty, do you have a perfomance hit by not having /boot on a separate partition? Sorry if this is a dumb question, but I was told that it is a perfomance hit if /boot is NOT a pertition...

Dusty · 2005-07-07 23:29:38

kcy29581 wrote:

So Dusty, do you have a perfomance hit by not having /boot on a separate partition? Sorry if this is a dumb question, but I was told that it is a perfomance hit if /boot is NOT a pertition...

I guess I don't know becaues I've never really done it any other way. Um... well, I install lilo to the MBR, which basically just copies files from /boot. To the best of my knowledge, /boot is thus not accessed during bootup. Maybe I'm wrong about that.

Dusty

iphitus · 2005-07-08 01:12:38

I just left it on the / partition of my arch system. I run my own kernels on any other distro I install, so I just boot into Arch and make a new entry for that distr.

kcy29581 · 2005-07-08 13:01:34

cool, I think that's what I'm gonna do on this system. I know how to make the entries in grub, that's not a problem. But obviously on bootup I can only have 1 bootable partition, so do I have to copy just the relevant kernel images from all distros to Arch's /boot for them to work, or do I also need to copy their coresponding System.map's?

Thanks for the info guys

iphitus · 2005-07-08 13:05:45

kcy29581 wrote:

cool, I think that's what I'm gonna do on this system. I know how to make the entries in grub, that's not a problem. But obviously on bootup I can only have 1 bootable partition, so do I have to copy just the relevant kernel images from all distros to Arch's /boot for them to work, or do I also need to copy their coresponding System.map's?
Thanks for the info guys

1 bootable partition, old old old wives tale nowadays.

Your system boots, brings up the MBR, from that you could pass onto a bootloader on any partition or boot linux with a root fs on any partition.

you could have a bootloader on your mbr that passes onto another bootloader on hda1, which passes onto another grub/lilo on hda5 which passes to another one on hda6, etc etc. and any of them can boot a linux with a root partition on any partition.

iphitus

kcy29581 · 2005-07-08 13:35:56

yep, I definately need to read up more...

thanks iphitus for the info.

kcy29581 · 2005-07-08 22:26:34

iphitus wrote:

kcy29581 wrote:
cool, I think that's what I'm gonna do on this system. I know how to make the entries in grub, that's not a problem. But obviously on bootup I can only have 1 bootable partition, so do I have to copy just the relevant kernel images from all distros to Arch's /boot for them to work, or do I also need to copy their coresponding System.map's?
Thanks for the info guys
1 bootable partition, old old old wives tale nowadays.
Your system boots, brings up the MBR, from that you could pass onto a bootloader on any partition or boot linux with a root fs on any partition.
you could have a bootloader on your mbr that passes onto another bootloader on hda1, which passes onto another grub/lilo on hda5 which passes to another one on hda6, etc etc. and any of them can boot a linux with a root partition on any partition.
iphitus

so iphitus, why do we have to make the partition where /boot is on "Active" during installation? Is this just to temporarily be able to read the kernel-image? I'm confused on this still...

kcy29581 · 2005-07-09 00:45:28

sorry, I'm going to answer my own question again... :oops:

I think I see what you meant iphitus. I think you were reffering to Grub's ability to chainload with the (duh!) chainloader option!

I think I've got all this now, to a level where I can safely install Suse after Arch. I've made space for Suse and instructed YAST to install Grub in the boot sector of Suse's designated /boot partition. I'll then modify Arch's /boot/grub/menu.lst by putting:

title Suse 9.3
root /dev/sdb1 (that's where I installed Suse/Suse's Grub)
chainloader +1

Hopefully I've understood Grub's manual!

Arch Linux

#1 2005-07-07 19:21:43

sharing /boot. Good or Bad idea?

#2 2005-07-07 19:26:05

Re: sharing /boot. Good or Bad idea?

#3 2005-07-07 19:32:15

Re: sharing /boot. Good or Bad idea?

#4 2005-07-07 19:44:46

Re: sharing /boot. Good or Bad idea?

#5 2005-07-07 20:11:48

Re: sharing /boot. Good or Bad idea?

#6 2005-07-07 20:38:49

Re: sharing /boot. Good or Bad idea?

#7 2005-07-07 21:45:33

Re: sharing /boot. Good or Bad idea?

#8 2005-07-07 22:11:34

Re: sharing /boot. Good or Bad idea?

#9 2005-07-07 22:28:08

Re: sharing /boot. Good or Bad idea?

#10 2005-07-07 23:09:15

Re: sharing /boot. Good or Bad idea?

#11 2005-07-07 23:29:38

Re: sharing /boot. Good or Bad idea?

#12 2005-07-08 01:12:38

Re: sharing /boot. Good or Bad idea?

#13 2005-07-08 13:01:34

Re: sharing /boot. Good or Bad idea?

#14 2005-07-08 13:05:45

Re: sharing /boot. Good or Bad idea?

#15 2005-07-08 13:35:56

Re: sharing /boot. Good or Bad idea?

#16 2005-07-08 22:26:34

Re: sharing /boot. Good or Bad idea?

#17 2005-07-09 00:45:28

Re: sharing /boot. Good or Bad idea?

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