Do You Partition Boot Seperatley?

Carlwill · 2010-11-13 15:48:07

I was wondering if you generally partition /boot separately from your / partition or do you just combine the two? Also I was wondering if it's recommended to partition my single /boot partition as 'ext2' or 'ext4'? I was told that it's pointless to partition /boot as ext4 since journaling serves no significance in /boot and only wastes space. Anyone care to comment on this?

Thanks

toad · 2010-11-13 15:56:31

Before Arch crossed my path I had a number of different systems on my box. I started off with a separate /boot (ext2) but soon became too lazy and just let the latest grub win.

Carlwill · 2010-11-13 16:04:06

toad wrote:

but soon became too lazy and just let the latest grub win.

I'm not sure I understand what that means.

SiD · 2010-11-13 16:07:23

I have to use a separately /boot partition to be able to boot because the other (root /tmp and /home) partitions are encrypted with LUKS.

Last edited by SiD (2010-11-13 16:08:11)

ewaller · 2010-11-13 16:12:32

If the system is just for me, no. If there are multiple users on a system, the best practice seems to be to have it as a separate partition and not to have it mounted after boot -- IIRC, There seems to be some advantage to this from a security standpoint.

Ashren · 2010-11-13 16:24:42

A separate ext4 boot partition when using lvm2 with grub. Haven't yet tried booting lvm2 from grub2.

thayer · 2010-11-13 16:27:41

No, I use a single root partition for each distro; I don't mess around with a separate /home, /boot, etc.

There's no point to journaling /boot (ext3/ext4) because the data stored there is static for the most part; it's overkill.

A separate /boot can be helpful should your root partition fill up or become corrupt, but these days it's so easy to boot with a LiveUSB in the event something goes wrong.

toad · 2010-11-13 17:11:24

Carlwill wrote:

toad wrote:
but soon became too lazy and just let the latest grub win.
I'm not sure I understand what that means.

Install whatever new system and have its grub recognize the other systems. In case that didn't work I got the stanzas together and put them in the latest grub - hope that makes sense.

thestinger · 2010-11-13 17:36:57

You can use ext4 without a journal, so there's no point having an extra filesystem module loaded (or compiled into the kernel) if your / is also ext4. ext4 is also faster than ext2, so why slow down your boot times?

Grub can't boot from btrfs, so if your / is btrfs, you actually need a /boot (grub2 might support it, I haven't checked). This is why I use a separate /boot on my old desktop.

Separating /tmp, /var and /home has huge security benefits due to hardlink/symlink vulnerabilities (world writable dirs are evil!) and it lets you set noexec, nodev and nosuid where there are appropriate. There's really no meaningful security benefit for separating /boot since only root can write there... and if root is compromised, it's over. If you left it unmounted, you would have to mount it during kernel upgrades anyway.

Last edited by thestinger (2010-11-13 17:37:38)

cirkit · 2010-11-13 17:53:33

Carlwill wrote:

I was wondering if you generally partition /boot separately from your / partition or do you just combine the two?

I always put /boot on its own separate partition. Say you mount / via NFS, clearly you would want /boot on a local partition. There are a ton of other reasons why its a good idea to have /boot separate from the rootfs.

Also I was wondering if it's recommended to partition my single /boot partition as 'ext2' or 'ext4'? I was told that it's pointless to partition /boot as ext4 since journaling serves no significance in /boot and only wastes space.

I find it redundant to use a journaling filesytem for /boot since ext2 is just ext3 without journaling. Really, /boot is only accessed at boot time, directly by the boot loader to get a boot image/initrd, so the journal is never used which ultimately would just waste space with no significant benefits whatsoever.

orlandu63 · 2010-11-13 19:51:56

cirkit wrote:

Carlwill wrote:
I was wondering if you generally partition /boot separately from your / partition or do you just combine the two?
I always put /boot on its own separate partition. Say you mount / via NFS, clearly you would want /boot on a local partition. There are a ton of other reasons why its a good idea to have /boot separate from the rootfs.
Also I was wondering if it's recommended to partition my single /boot partition as 'ext2' or 'ext4'? I was told that it's pointless to partition /boot as ext4 since journaling serves no significance in /boot and only wastes space.
I find it redundant to use a journaling filesytem for /boot since ext2 is just ext3 without journaling. Really, /boot is only accessed at boot time, directly by the boot loader to get a boot image/initrd, so the journal is never used which ultimately would just waste space with no significant benefits whatsoever.

What problems does mounting / via NFS without a separate boot partition bring? You can still mount your local /boot over the remote /boot, even when the latter is not empty.

cirkit · 2010-11-13 20:12:42

What problems does mounting / via NFS without a separate boot partition bring? You can still mount your local /boot over the remote /boot, even when the latter is not empty.

Well, it does not really bring any problems. But if the remote host did not have a /boot and only used / I do not know how you could mount local /boot over the remote /boot.

Primoz · 2010-11-13 22:01:58

You don't need to have a boot partition??? And it's not considered unsafe?
Wow, well I guess I know how my next partitioning will go...
Still I think I'll leave /home on different partition just in case.

(I also won't have swap partition, but rather a swapfile, but I do have this already...)

arinlares · 2010-11-14 00:15:26

I boot Arch and Debian (or anything that should catch my fancy without too much work involved), so I use two / partitions, and a /home partition. I figure I could probably just set Grub up to use my other OS's root to boot should Arch go down (despite my dislike for Grub 2).

vadmium · 2010-11-14 02:13:46

I've got a 200 MB FAT boot partition. My original theory was it's a simple file system and the lowest common denominator between Linux and Windows, so I could easily edit the Grub menu from Windows and remotely reboot or something. However I don't even have a bootable Windows setup these days, but I think having one single boot partition shared by all OS installs is the neatest way to go.

erje · 2010-11-14 11:13:13

arinlares wrote:

I boot Arch and Debian (or anything that should catch my fancy without too much work involved), so I use two / partitions, and a /home partition. I figure I could probably just set Grub up to use my other OS's root to boot should Arch go down (despite my dislike for Grub 2).

Is it possible to share a /boot between installations?

That is, I'd like to put Arch and Debian on the same box in a dual boot arrangement. In Arch I follow the default of having /boot, /, swap, and /home on their own partitions.

I'd like to share swap, /home, and /boot between Arch and Debian so I don't have a lot of unnecessary partitions on my disk. Sharing swap and /home is easy.

I don't what'd be required to share /boot. I know /boot is where the kernel resides, so I'd have to put the Debian kernel there along with an appropriate entry in GRUB. Anything else?

orlandu63 · 2010-11-14 13:42:22

cirkit wrote:

What problems does mounting / via NFS without a separate boot partition bring? You can still mount your local /boot over the remote /boot, even when the latter is not empty.
Well, it does not really bring any problems. But if the remote host did not have a /boot and only used / I do not know how you could mount local /boot over the remote /boot.

It's no less simple than mounting a partition over an empty directory

orlandu63 · 2010-11-14 13:52:34

erje wrote:

arinlares wrote:
I boot Arch and Debian (or anything that should catch my fancy without too much work involved), so I use two / partitions, and a /home partition. I figure I could probably just set Grub up to use my other OS's root to boot should Arch go down (despite my dislike for Grub 2).
Is it possible to share a /boot between installations?
That is, I'd like to put Arch and Debian on the same box in a dual boot arrangement. In Arch I follow the default of having /boot, /, swap, and /home on their own partitions.
I'd like to share swap, /home, and /boot between Arch and Debian so I don't have a lot of unnecessary partitions on my disk. Sharing swap and /home is easy.
I don't what'd be required to share /boot. I know /boot is where the kernel resides, so I'd have to put the Debian kernel there along with an appropriate entry in GRUB. Anything else?

Every distribution has its own way of initializing the kernel and its own /boot filesystem hierarchy, which is why it makes it so hard to share /boot partitions between distributions. This is exactly why I don't have a separate /boot partition: it most cases, the /boot hierarchy is designed in terms of the particular distribution, not in terms of a common structure or standard (someone should change that). So in effect, separating your /boot partition for reuse is about as silly as separating your /etc partition for reuse. (To answer your question: of course it's possible, but it's neither simple nor rewarding.)

Last edited by orlandu63 (2010-11-14 13:57:15)

ChoK · 2010-11-14 14:33:20

orlandu63 wrote:

erje wrote:
arinlares wrote:
I boot Arch and Debian (or anything that should catch my fancy without too much work involved), so I use two / partitions, and a /home partition. I figure I could probably just set Grub up to use my other OS's root to boot should Arch go down (despite my dislike for Grub 2).
Is it possible to share a /boot between installations?
That is, I'd like to put Arch and Debian on the same box in a dual boot arrangement. In Arch I follow the default of having /boot, /, swap, and /home on their own partitions.
I'd like to share swap, /home, and /boot between Arch and Debian so I don't have a lot of unnecessary partitions on my disk. Sharing swap and /home is easy.
I don't what'd be required to share /boot. I know /boot is where the kernel resides, so I'd have to put the Debian kernel there along with an appropriate entry in GRUB. Anything else?
Every distribution has its own way of initializing the kernel and its own /boot filesystem hierarchy, which is why it makes it so hard to share /boot partitions between distributions. This is exactly why I don't have a separate /boot partition: it most cases, the /boot hierarchy is designed in terms of the particular distribution, not in terms of a common structure or standard (someone should change that). So in effect, separating your /boot partition for reuse is about as silly as separating your /etc partition for reuse. (To answer your question: of course it's possible, but it's neither simple nor rewarding.)

Actually no, /boot is populated by grub/grub2/lilo, the only differences between the distros are in the kernel/initramfs. Therefore they can coexist. (Chakra, arch, ubuntu coexist just fine on my laptop. Mandriva used to work just fine too.)

Last edited by ChoK (2010-11-14 14:35:42)

pseudonomous · 2010-11-15 15:22:49

ChoK wrote:

orlandu63 wrote:
erje wrote:
... Is it possible to share a /boot between installations? ...
... Every distribution has its own way of initializing the kernel and its own /boot filesystem hierarchy ...
Actually no, /boot is populated by grub/grub2/lilo, the only differences between the distros are in the kernel/initramfs. Therefore they can coexist. (Chakra, arch, ubuntu coexist just fine on my laptop. Mandriva used to work just fine too.)

I may be wrong here, but I do think it's actually the distro tools that populate Grub config files in /boot. In the case of arch, the installer generates the initial grub config files, and afterwards they never get regenerated again. However, in Debian (so probably also Ubuntu), the grub config files get regenerated any time you update or install a kernel package. Meanwhile, in RHEL/CentOS the config file names for grub are different than in either Arch or Debian, i.e. grub.conf vs. menu.lst.

It's certainly possible to share /boot between different distros, but there are a few things you need to be careful about, as I've listed above.

combuster · 2010-11-15 16:08:24

Last time I had separate boot partition was some 10 years ago (roughly estimated) cause I remember that LILO couldn't boot from the partition with more than 1024 cylinders.

I have always only one partition for Arch, one partition for Arch to play with, partition for backup and swap partition. All of them are primary and that's it. I don't back up home partition either cause I always have essential backup of system/user configuration files on my flash drive JIC.

MkFly · 2010-11-15 22:25:26

SiD wrote:

I have to use a separately /boot partition to be able to boot because the other ... partitions are encrypted with LUKS.

Yep, me too. /boot is ext2, and then the rest of my drive is taken up by an encrypted LVM (LVM on a LUKS partition).

ANOKNUSA · 2010-11-25 04:30:17

thestinger wrote:

You can use ext4 without a journal, so there's no point having an extra filesystem module loaded (or compiled into the kernel) if your / is also ext4. ext4 is also faster than ext2, so why slow down your boot times?
Grub can't boot from btrfs, so if your / is btrfs, you actually need a /boot (grub2 might support it, I haven't checked). This is why I use a separate /boot on my old desktop.

It's my understanding that GRUB2 can't read btrfs either; rather, a separate ext2 boot partition should be used. I'm looking to try out btrfs, and was wondering if it's possible to migrate /boot to it's own partition. I'll have to look into that. That's a fine example of the tinkering myself and others like to do--which is why I keep a separate /home partition and us Clonezilla to take a snapshot of my root partition twice a week. If I screw something up, I can just restore the backup or easily reinstall without any real loss.

mikesd · 2010-11-25 05:51:16

thestinger wrote:

Grub can't boot from btrfs, so if your / is btrfs, you actually need a /boot (grub2 might support it, I haven't checked). This is why I use a separate /boot on my old desktop.

I use a single btrfs partition on my netbook and boot with extlinux. It supports ext and btrfs. Another option besides GRUB/GRUB2.

Arch Linux

#1 2010-11-13 15:48:07

Do You Partition Boot Seperatley?

#2 2010-11-13 15:56:31

Re: Do You Partition Boot Seperatley?

#3 2010-11-13 16:04:06

Re: Do You Partition Boot Seperatley?

#4 2010-11-13 16:07:23

Re: Do You Partition Boot Seperatley?

#5 2010-11-13 16:12:32

Re: Do You Partition Boot Seperatley?

#6 2010-11-13 16:24:42

Re: Do You Partition Boot Seperatley?

#7 2010-11-13 16:27:41

Re: Do You Partition Boot Seperatley?

#8 2010-11-13 17:11:24

Re: Do You Partition Boot Seperatley?

#9 2010-11-13 17:36:57

Re: Do You Partition Boot Seperatley?

#10 2010-11-13 17:53:33

Re: Do You Partition Boot Seperatley?

#11 2010-11-13 19:51:56

Re: Do You Partition Boot Seperatley?

#12 2010-11-13 20:12:42

Re: Do You Partition Boot Seperatley?

#13 2010-11-13 22:01:58

Re: Do You Partition Boot Seperatley?

#14 2010-11-14 00:15:26

Re: Do You Partition Boot Seperatley?

#15 2010-11-14 02:13:46

Re: Do You Partition Boot Seperatley?

#16 2010-11-14 11:13:13

Re: Do You Partition Boot Seperatley?

#17 2010-11-14 13:42:22

Re: Do You Partition Boot Seperatley?

#18 2010-11-14 13:52:34

Re: Do You Partition Boot Seperatley?

#19 2010-11-14 14:33:20

Re: Do You Partition Boot Seperatley?

#20 2010-11-15 15:22:49

Re: Do You Partition Boot Seperatley?

#21 2010-11-15 16:08:24

Re: Do You Partition Boot Seperatley?

#22 2010-11-15 22:25:26

Re: Do You Partition Boot Seperatley?

#23 2010-11-25 04:30:17

Re: Do You Partition Boot Seperatley?

#24 2010-11-25 05:51:16

Re: Do You Partition Boot Seperatley?

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