[arch-general] Removing initrd (For use with GRUB2, LVM, GPT)

[Jonathan Vasquez]

On Thu, Jan 12, 2012 at 12:36 AM, C Anthony Risinger <anthony at xtfx.me> wrote:
> On Wed, Jan 11, 2012 at 10:29 PM, Jonathan Vasquez
> <jvasquez1011 at gmail.com> wrote:
>>
>> Simplicity and minimalism would be what motivates me the most. If I
>> don't need an initramfs to get my system boot up, why have one? I know
>> the benefits that initramfs provides, but I don't need any of them.
>> All I need my computer to do is start, find the kernel, boot my comp
>> to the terminal or X11 (depending on my setup).
>
> well, i hear ya, but i'd argue you already *have* the minimalist setup
> ... life is about balance friend :-)  i'm not sure too many would
> agree (my time is more important that pedantic minimalism) hence
> support may be hard to come by.  although, this paragraph is backed by
> little more than imaginary statistics and [possibly misguided]
> intuition.

Well I'm not trying to be minimalistic just to be minimalistic. I'm
picky about how my things are organized on my system, and the files I
have installed.
If I have the power to remove something unnecessary, then I most
likely will remove it ;). I do agree with you that life is about
balance. I might go back to using an initramfs,
but not atm, probably when I learn how to make my own basic initramfs
haha with busybox and my own /init script (For learning purposes
primarily).

>> My set up atm that lets me have GPT, GRUB2, LVM, all without needing
>> initramfs, and future proofs me the need to move the physical
>> partitions in the drive (not the logical ones inside the lvm) is:
>>
>> /dev/sda1 BIOS Boot Partition    32M
>> /dev/sda2 /boot   ext2    100M
>> /dev/sda3 /         ext4    2G
>> /dev/sda4  Linux LVM (name: arch)
>
> ... because you desire to drop the initramfs, you've lost the ability
> to manage / with LVM2, and that sux.  2GiB *might* be enough, never
> was nearly enough for me (though, i reject the idea of oodles of
> partitions) ... but what if it's not?  by generating a teeny 4Mib
> file, you're / moves to LVM2, and you never have to rebuild the kern
> if you change FS, change hardware, change <insert here> ... dunno,
> nice trade off to me ... won't say anything further about it ;-)

Yea.. I know it sucks.. previously my set up was just as you said, I
still have that setup in my old Arch drive (That I haven't formatted).
I'm assuming you already know how my old setup was since you mentioned
me losing the ability to manage / under LVM2. 2GB is more than needed,
1GB would be more minimal,
but you just have to make sure you use the other partitions inside of
the LVM, since /usr, /var , etc take up a lot of space for
applications and packages. I agree, for a small initramfs I gain a
lot.
I wanted to see if this was possible under Arch, under my setup,
clearly it is, but it has a cost :(.

As for rebuilding the kernel, I built support for ext2/3/4 directly
into the kernel. So if I need to switch to btrfs, I can recompile yes,
but it only takes me like 5-7 minutes to rebuild since my kernel is
just for my computer. I could also rebuild it months in advance with
btrfs support as well and not have to worry about it later on :).
Changing hardware, I hardly do this anymore, so doesn't really affect
me, if this happens, then I would gladly explore the kernel
configuration again and learn about my new system :).

>> Created in a (read most, write last order .. if it matters inside LVM)
>> /dev/arch/swap   2G
>> /dev/arch/usr      10G
>> /dev/arch/tmp     10G
>> /dev/arch/opt      5G
>> /dev/arch/var      10G
>> /dev/arch/home  500G
>
> btw, if swap is on LVM2, you'll want to flag it contiguous (-Cy on
> `lvcreate`) if you didn't already.  also, not sure if you need it, but
> hibernation will be impossible without initramfs if swap is on LVM2.
> lastly, be aware that a separate `/usr` is rapidly degrading into a
> next-to-unsupported/awkwardly-handled configuration ... while a lack
> of initramfs avoids the need to mount it pre-root, you may still have
> issues during early boot ... especially since soon, if not now, Arch
> initscripts will fully expect `/usr` to be available before pid 1 (Tom
> or someone else would need to confirm this).

Yup, my swap was made contiguous. I don't hibernate and took that into
account when making my partition layouts. I just suspend to ram which
can be done still in my layout. That would be an unfortunate event if
I am required to have to do some of those things.

> --
>
> C Anthony

Overall, as I said in the beginning, I may end up going back to using
an initramfs to simplify the partition layouts in general. Using an
initramfs, pretty much, has nothing but advantages.

Although hacking to see if something is possible surely is fun, .. if
only for a while.
-- 
Jonathan Vasquez