Gentoo Archives: gentoo-user

From: Michael Mol <mikemol@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Re: After /usr conflation: why not copy booting software to /sbin rather than initramfs?
Date: Thu, 29 Mar 2012 17:16:45
Message-Id: CA+czFiBUBW5obnfb6KF0+kv-mEpSZ3TZJESdiupbbE+WmZ8Q3g@mail.gmail.com
In Reply to: Re: [gentoo-user] Re: After /usr conflation: why not copy booting software to /sbin rather than initramfs? by Neil Bothwick
1 On Thu, Mar 29, 2012 at 12:35 PM, Neil Bothwick <neil@××××××××××.uk> wrote:
2 > On Thu, 29 Mar 2012 15:56:28 +0000, Alan Mackenzie wrote:
3 >
4 >> > Well, for one, the initramfs solution is not generally considered
5 >> > "ugly" except by a select vocal few who object to it on vague,
6 >> > unarticulated grounds.
7 >>
8 >> I'll articulate a few.  (i) The initramfs involves having two copies of
9 >> lots of software around.
10 >
11 > Lots? For most people busybox is enough! If you want encrypted
12 > filesystems on LVM over RAID that rises to a total of four executables.
13
14 And anything they might conceivably link to. Not everything supports
15 static linking.
16
17 Don't forget boot-time X-based animation, too. That's an
18 extraordinarily common feature of mainstream desktop distributions.
19 And there will be other things, I'm sure.
20
21 >> (ii) What's more, these two copies are often
22 >> different, one being built with static libraries, the other with dynamic
23 >> ones.  (iii) This situation is not (as far as I know) yet handled by
24 >> Portage, which means in building such software statically, you've got to
25 >> save the dynamic version somewhere else whilst you're doing it.
26 >
27 > That's wrong. For example, LVM builds dynamic executable plus the
28 > lvm.static file for use in the initramfs.
29
30 That's exactly what Alan just noted in (ii), but perhaps portage
31 handles (iii) in the case of LVM.
32
33 >> (iv)
34 >> The initramfs requires a potentially long script to make it work.
35 >
36 > Mount /proc, /sys and /dev.
37 > Mount root
38 > Unmount /proc, /sys and /dev.
39 > switch_root
40
41 Things look much simpler when you abstract away the details. You still
42 have to manage lvm, mdraid and whatever else is necessary for mounting
43 things. That's where 'potentially long' came from, I expect.
44
45 >> I think that qualifies the initramfs solution as ugly.
46 >
47 > Only if you build the initramfs with USE="fud".
48
49 FUD: "Fear, uncertainty and doubt"
50
51 In short, three things which are important to rationally examine and
52 deal with on a case-by-case basis.
53
54 Fear of risk is healthy when trying to maintain something.
55
56 Uncertainty is expected when you first launch into some brave, new
57 world, and it's necessary to to learn things well enough to be able to
58 rule out uncertain conditions. That's an intrinsic part of systemic
59 stability.
60
61 Doubt is another word for risk analysis. What are the chances this
62 will fail, versus the chance that that will fail? What's the cost of
63 each of these failures.
64
65 --
66 :wq

Replies