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leonchik1976
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PostPosted: Thu Oct 08, 2015 11:58 am    Post subject: Separate /boot Reply with quote

Hi, i have a question - do i really need a separate /boot partition?
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frostschutz
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PostPosted: Thu Oct 08, 2015 12:00 pm    Post subject: Reply with quote

Hi, i have an answer - it depends. :wink:
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leonchik1976
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PostPosted: Thu Oct 08, 2015 12:07 pm    Post subject: Reply with quote

i have /boot/efi formatted as vfat, on what it depends?
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mrbassie
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PostPosted: Thu Oct 08, 2015 4:05 pm    Post subject: Reply with quote

leonchik1976 wrote:
i have /boot/efi formatted as vfat, on what it depends?


Do you want one?

It does have it's advantages. Can't think of a disadvantage.
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NeddySeagoon
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PostPosted: Thu Oct 08, 2015 5:26 pm    Post subject: Reply with quote

leonchik1976,

Since the earliest days of the PC there has been a race between hard drive vendors to produce bigger hard drives and BIOS vendors to update the BIOS to be able to boot from. them. The problem first occured when HDD reached 528MB. (Yes MB).

What happened was that the BIOS could no longer read the entire hard drive. As the BIOS is used to load the kernel and initrd, if those files were located on the HDD outside of the region redable by the BIOS, booting would fail.
The workaround was a small /boot partition located at the start of the drive. That ensured the BIOS could almays read files needed for booting.
This problem will occur again when HDD exceed 256PB, which is a few years away yet.

grub2 can boot from all sorts of exotic disk setups. RAID, LVM and so on, which would normally require a separate /boot.
If you have an encrypted disk you probably need an unencrypted /boot but I'm not a grub2 user, so don't quote me.
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khayyam
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PostPosted: Thu Oct 08, 2015 8:43 pm    Post subject: Reply with quote

NeddySeagoon wrote:
If you have an encrypted disk you probably need an unencrypted /boot but I'm not a grub2 user, so don't quote me.

Neddy ... no, not really, if there is an ESP (EFI System Partition) on /boot/efi then this can function as '/boot' (ie, hold the kernel, initramfs, etc) and so encrypted root is fine.

@leonchik1976 ... I'd generally advise against grub2, use some other EFI capable bootloader/bootmanager (rEFInd, gummyboot).

best ... khay
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cwr
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PostPosted: Fri Oct 09, 2015 11:18 am    Post subject: Reply with quote

I use a separate boot partition because it saves having to reinstall grub (or any bootloader, I guess)
if I move or reinstall my root partition. I just set up the Windows boot menu to boot a given partition,
the Grub partition, and that's that for the life of the machine.

Will
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steveL
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PostPosted: Fri Oct 09, 2015 3:53 pm    Post subject: Reply with quote

It's much more convenient, as cwr said.

You set aside a few hundred MB for /boot, and can do what you want in the rest.

Sounds like efi simply requires that, so you already have a boot partition, from what khayyam wrote.

Repartitioning is a lot simpler when /boot is a given, for sure, as is messing around with other distros.
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kernelOfTruth
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PostPosted: Fri Oct 09, 2015 10:52 pm    Post subject: Reply with quote

++

What cwr and steveL said
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https://github.com/kernelOfTruth/pulseaudio-equalizer-ladspa

Hardcore Gentoo Linux user since 2004 :D
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Tony0945
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PostPosted: Sat Oct 10, 2015 12:14 am    Post subject: Reply with quote

steveL wrote:


Repartitioning is a lot simpler when /boot is a given, for sure, as is messing around with other distros.


Yes, I just installed Ubuntu today in some free space on the disk. I told the installer to install grub (grub2) on the partition (/dev/sdb6). then rebooted
into Gentoo and edited /boot/grub/grub.conf (grub legacy) with three simple lines to chain load /dev/sdb6. I guess I could do that with /boot on the root partition also, but this way the (Gentoo) root partition doesn't have to be mounted at all to chainload Windows or Ubuntu (RedHat windows 8).
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Roman_Gruber
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PostPosted: Sat Oct 10, 2015 8:56 am    Post subject: Reply with quote

khayyam wrote:
NeddySeagoon wrote:
If you have an encrypted disk you probably need an unencrypted /boot but I'm not a grub2 user, so don't quote me.

Neddy ... no, not really, if there is an ESP (EFI System Partition) on /boot/efi then this can function as '/boot' (ie, hold the kernel, initramfs, etc) and so encrypted root is fine.

@leonchik1976 ... I'd generally advise against grub2, use some other EFI capable bootloader/bootmanager (rEFInd, gummyboot).

best ... khay


+1. WAs a pain to get my box booting. hardly any docs about luks/lvm on uefi. (I did it a few days ago, and i struggled for days because I did not wanted to use something else as grub2. Partly issues with uefi / partly with gpt partition table / a lot of issues with grub2 / a few issues with the genkernel intramfs. I ended up disassemblying the initramfs and reading the hole init process to get my box to boot. Hardly documented on the web what it really needs.

General it anoys me that the gentoo handbook or uefi needs vfat. On every unclean shutdown i get the annoying message, partitoin bla bla is not mounted dirty. => fsck /partition => dirty bit set? wanna fix, yes. does nothing. Because I reboot from sysrescue-cd a lot (the dirty bit is set quite often on /boot (uefi vfat) thing like recommended on the handbook)


@ toni, did your binary distro overwrote any important settings / system partitions?

Code:
sgdisk -p /dev/sda
Disk /dev/sda: 250069680 sectors, 119.2 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): "removed"
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 250069646
Partitions will be aligned on 2048-sector boundaries
Total free space is 4029 sectors (2.0 MiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048            6143   2.0 MiB     EF02  grub
   2            6144          268287   128.0 MiB   EF00  boot
   3          268288          530431   128.0 MiB   8300  reserved_for_future...
   4          530432       250067631   119.0 GiB   8300  root_filesystem


Partition 1, as said on the handbook
partition 2, only 128mb, Windows 10 for example makes it 400 or 500mb (installed windows 10 a week ago)
Partition 3, small partition with extra junks, the label is not shown properly on this tool. some guides suggests to add 128mb after the boot partition. When I may need a few spare MB i have those there.
partition 4. root => pv 100%, vg/lv ~99.x %, ~100-200mb free phyiscal extents (because of mirror or something else, than lvm needs one phyisical extents which i reserved this time)

What I saw so far with windows 10 and gentoo. I think you need a separate boot with uefi bios. All the guides i had to read because the root was not booted properly suggested up to 500mb separate boot.

I think 128mb is a very decent value for /boot. Smaller is even a pain.
On a second thought, 1GB /boot with sysrescue-cd as iso on /boot may be wise to chainload, but i do not have the luxuary on a 120GB only SSD (more a money issue here, i can not afford to spend lots of money in hardware).
Code:
df -h /boot
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda2       128M   47M   82M  37% /boot


When you want to critise space waste, you need to consider that my previous installations started with sector 63. and this here now on sector 2048. I follow the handbook but I do not get the book why boot needs to be aligned to the sectors?
As you can see: First usable sector is 34 => means sector 34- 2047 is unused. i think we talk about 1-2mB spacewaste but still it is waste.
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Tony0945
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PostPosted: Sat Oct 10, 2015 3:43 pm    Post subject: Reply with quote

tw04l124 wrote:
@ toni, did your binary distro overwrote any important settings / system partitions?


No. I carefully read the prompts and chose not to format any partitions (had already formatted with gparted from Gentoo) and chose to install the bootloader in the partition (probably wouldn't have mattered if I was already using grub2). But I had my heart in my throat as the drive lit lit up and stayed on and the screen only showed that idiot splash screen with five moving dots.

I use a rather unconventional setup. The BIOS boots the first hard drive which is XP. The XP bootloader has an image of the second drive's boot sector as a choice (actually the default) which boots the second drive's boot sector which is grub 0.97 (aka grub legacy). Now to get to Ubuntu, one chooses the sixth partition chain loader titled "Ubuntu" which chain load's grub2 from the sixth partition. Surprisingly, it all boots faster than XP and NONE of the partitions are vfat. All are either ntfs or ext4. The third drive stores videos, it's ntfs accessed by either Gentoo (mounted as /video) with the ntfs-3g driver or by Windows as drive V:

I don't like FAT either. Why didn't M$ make that partition NTFS?

BTW: Ubuntu is S-L-O-W. It['s 14.something with GNOME 3. Don't know if it's systemd or not. I HATE it. No terminal so I keep switching between VT1 to work and VY7 to read web instructions. Why is this so popular that in the public's mind it's synonymous with Linux?
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Roman_Gruber
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PostPosted: Sat Oct 10, 2015 4:49 pm    Post subject: Reply with quote

i use or used a lot linux mint next to gentoo. it is based on ubuntu which is based on debian.

well lets phrase it, it is the easiest among the linux distros for the average windows guy without much computer knowledge or will to learn. And for myself linux mint worked out of the box, where suse linux, turbolinux, fedora core had their issues. i used mint as last ressort because i dislike ubuntu also. Mint is just an install and forget distro, which just worked for myself over the years. Nevertheless linux mint overwrote without user confirmation, with the graphical user interface updater my hole grub.cfg with the gentoo settings in them. For the average user who has one harddisc, install one operating system or may dual boot, linux mint is fine, else you may ask for issues ...
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Tony0945
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PostPosted: Sat Oct 10, 2015 6:24 pm    Post subject: Reply with quote

tw04l124, I had that problem with Fedora. Years ago, I prepared a hard disk with three Linices for a friend, Ubuntu (Fiesty Fawn), Fedora (4?) and Gentoo. Fedora wrote all over the others d I had to reinstall Ubuntu and Gentoo. I still had to give a separate /home to Fedora. I was trying to have a single /home so he could explore the differnces but Fedora would not play nicely.

I once had Kubuntu and it was OK if you like KDE. Ubuntu was probably OK before Gnome 3. But now it's as slow as using systemrescuecd from an actual CD (it's pretty fast if you take the option to load the whole CD into memory).
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Cyker
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PostPosted: Sat Oct 10, 2015 8:38 pm    Post subject: Reply with quote

There is always the risk a separate /boot won't be supported in the future :lol: :P
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Tony0945
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PostPosted: Sat Oct 10, 2015 10:00 pm    Post subject: Reply with quote

Cyker wrote:
There is always the risk a separate /boot won't be supported in the future :lol: :P


Well as mentioned above, with UEFI it's de facto sperate boot. And if not, it's easy enough to bring the separate boot inside.
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khayyam
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PostPosted: Sat Oct 10, 2015 10:25 pm    Post subject: Reply with quote

tw04l124 wrote:
+1. WAs a pain to get my box booting. hardly any docs about luks/lvm on uefi. (I did it a few days ago, and i struggled for days because I did not wanted to use something else as grub2. Partly issues with uefi / partly with gpt partition table / a lot of issues with grub2 / a few issues with the genkernel intramfs. I ended up disassemblying the initramfs and reading the hole init process to get my box to boot. Hardly documented on the web what it really needs.

tw04l124 ... you should have asked me ;) ... I've made quite a number of posts on that exact setup in the past few years, and it isn't too difficult once you understand the basics.

tw04l124 wrote:
General it anoys me that the gentoo handbook or uefi needs vfat. On every unclean shutdown i get the annoying message, partitoin bla bla is not mounted dirty. => fsck /partition => dirty bit set? wanna fix, yes. does nothing. Because I reboot from sysrescue-cd a lot (the dirty bit is set quite often on /boot (uefi vfat) thing like recommended on the handbook)

It should need, or be, mounted, do you have partition coded 'EF00' and 'noauto' set in fstab?

Code:
# awk 'NR==18;/EFI/' <(gdisk -l /dev/sda)
Number  Start (sector)    End (sector)  Size       Code  Name
   1              40          409639   200.0 MiB   EF00  EFI System Partition
# awk '/boot/ && gsub(/[ |\t]+/," ")1' /etc/fstab
UUID="70D6-1701" /boot vfat noauto,defaults 0 0

Cyker wrote:
There is always the risk a separate /boot won't be supported in the future :lol: :P

hehe ... yeah, or forward slash ... org.freedeskflop.resource.path.boot.vmlinuz.dot.bz2 :P

HTH & best ... khay
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steveL
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PostPosted: Sun Oct 11, 2015 11:38 am    Post subject: Reply with quote

Cyker wrote:
There is always the risk a separate /boot won't be supported in the future :lol: :P

khayyam wrote:
hehe ... yeah, or forward slash ... org.freedeskflop.resource.path.boot.vmlinuz.dot.bz2 :P

LMAO.. though it's not far away what with all the go-fasterer replacement of fstab.
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