dracut, or should booting a LiveCD touch the hard disk?

[Hans de Goede]

On 10/04/2009 11:35 PM, Chuck Anderson wrote:
> Dracut currently tries to find and activate all RAID, LVM, and LUKS
> partitions on the hard disks when booting the LiveCD.
>
> Several of my systems are made up of many RAID, LVM, and LUKS
> partitions in various combinations.  Booting the LiveCD now goes and
> activates these and asks for passphrases that I have to "skip over" by
> entering blank/bogus values to get the system to boot up.  I now know
> that you can pass various "rd_*" options such as "rd_NO_LUKS" to grub
> to have dracut skip these things, but I was hoping for something
> better, perhaps a "skip" button.
>
> The new behavior makes the LiveCD less independent of and more "tied"
> to the existing installations on the hard disk.  This is surprising
> and unexpected.  Many uses of LiveCD's expect that the live
> environment will be completely independent of, and unaffected by, what
> is on the hard disk.  This is no longer true.  It may be confusing for
> users of LiveCD's when an (unidentified) passphrase input text box
> pops up when booting the LiveCD.
>
> What do others think?  Should the LiveCD by default access and
> activate storage volumes, including encrypted partitions, on the hard
> disks?  Should the LUKS prompts better identify the volume so that
> users know what passphrase to enter?
>
> I would prefer a LiveCD that doesn't do anything to the hard disk at
> all, at least by default when booting up.  It should be
> "self-contained".  Perhaps we should create another entry in
> syslinux.cfg that enables rd_NO_LUKS by default, and call it "Boot
> without accessing hard disk".
>

Hi,

Thanks for bringing this up. I'll create a patch for the scripts
generating the livecd to add rd_NO_LUKS to the normal livecd
syslinux.cfg entry. I already was planning on doing this, but I forgot.

Regards,

Hans