:: Re: [Dng] [dng] vdev status updates
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Autor: Steve Litt
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Dla: dng
Temat: Re: [Dng] [dng] vdev status updates
On Tue, 28 Apr 2015 20:03:02 -0400
Jude Nelson <judecn@???> wrote:


> * Packaging. I'm working on a way to automatically build a .deb for
> vdevd that will, among other things, safely generate and install an
> initramfs without having to hack the initramfs tools (as is the case
> today). Please see [Help Wanted].


[snip]


> * Astute readers may notice that one method in
> vdev/helpers/LINUX/subr.sh is called vdev_chown. This is because for
> whatever reason, Debian's busybox chown does not accept usernames and
> group names when running in the initramfs. I have tried:
> -- copying over /etc/passwd, /etc/passwd-, /etc/group, /etc/group- to
> the initramfs.
> -- using GNU chown.
> -- strace-ing both GNU chown and busybox to confirm that they access


[snip]

>
> * As Anto's experience shows, getting a working initramfs is tedious
> to do and easy to get wrong. This is not only because there are
> multiple init systems that vdevd will need to work with (e.g.
> sysv-rc, file-rc, openrc, etc.), but also init scripts and initramfs
> scripts that come from packages that depend on udev are
> (unsurprisingly) tightly coupled to udev.


Hi Jude,

You probably know this, but in case you don't, the Debian-User list
reports that Jessie itself has initramfs problems.

Let me ask you something else about initramfs...

What I say in the following paragraphs is based on the Epoch init
system and might not be useful with sysvinit, but maybe it might
help...

I'm under the impression you can do most or all of what needs to be
done in the actual init, rather than the initramfs. This gets a little
complicated now that Linux has been "improved" by having /sbin
and /bin be symlinks to /usr/bin, which might not be mounted in early
boot, but aside from that, I think once you have possession of /bin
and /sbin, then assuming that /etc is not a mountpoint, I think most
other stuff can be delayed til the real init, always assuming that it's
easier to put stuff in the on-disk init than in initramfs.

LOL, we could always cheat and put copies of programs that should be
in /sbin and /bin in the pre-mounted versions of those directories. Who
knows, maybe then we could eliminate the initramfs step entirely. :-)

I don't know how practical any of this would be, but I've never been a
big fan of initrd/initramfs, and the one on my Wheezy has hair and
teeth.

SteveT

Steve Litt
April 2015 featured book: Twenty Eight Tales of Troubleshooting
http://www.troubleshooters.com/28