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From: Ian Zimmerman <itz@very.loosely.org>
To: gentoo-user@lists.gentoo.org
Subject: [gentoo-user] Re: Using UUID for root disk in grub requires initramfs?
Date: Fri, 19 Jul 2019 09:37:16 -0700	[thread overview]
Message-ID: <20190719163716.l6lkpnwlrcxg3353@matica.foolinux.mooo.com> (raw)
In-Reply-To: <CAC=wYCG3DC7y+2XXprL9tzdZFkfO0ABa_qAVL07STwwqmyFeAQ@mail.gmail.com>

On 2019-07-19 20:58, Adam Carter wrote:

> I experimented found the following worked in /etc/default/grub;
> 
> GRUB_DEVICE="PARTUUID=d3554d49-02"
> 
> Which writes grub.cfg as;
> linux /vmlinuz-5.2.0-gentoo root=PARTUUID=d3554d49-02 ro
> init=/usr/lib/systemd/systemd iommu=pt raid=noautodetect
> 
> PARTUUID looked up with blkid. No initramfs required :)

I don't get this.  blkid is userspace.  The _kernel_ needs to know what
the root fs device is, before it even starts pid 1.

With initramfs, this egg/chicken problem is hidden: the initramfs itself
is the initial root fs, and during the pivot to the real root fs
userspace programs [1] are already available.

[1]
Well, usually just 1 of them: busybox.

-- 
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  reply	other threads:[~2019-07-19 16:37 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-19  9:29 [gentoo-user] Using UUID for root disk in grub requires initramfs? Adam Carter
2019-07-19 10:27 ` Mick
2019-07-19 10:58   ` Adam Carter
2019-07-19 16:37     ` Ian Zimmerman [this message]
2019-07-19 16:59       ` [gentoo-user] " Mike Gilbert
2019-07-19 23:19       ` Adam Carter

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