Starting an authenticated root shell is a security hole, so don't do
it by default. The kernel command line parameter
‘initrd.shell_on_fail’ restores the original. (Of course, this only
improves security if you have a password on GRUB to prevent the kernel
command line from being edited by unauthorized users.)
BusyBox doesn't handle the "auto" filesystem type very well: fsck will
just ignore such filesystems, and mount will only work properly if the
required kernel module is already loaded. Therefore, use blkid to
determine the filesystem type.
Also generate an /etc/fstab in the initrd rootfs on the fly. This is
useful if you're dropped into an emergency shell since it allows you
to say "fsck /dev/sda1" or "mount /dev/sda" and have the right thing
happen.
Using BusyBox instead of Bash plus a bunch of other tools gives us a
much more feature-full, yet smaller initrd. In particular, BusyBox
contains networking commands such as ip and a DHCP client, useful for
NFS boots. It's also much more convenient for rescue situations
because the shell has builtin readline support and there are many more
tools (including vi).
* Load scsi_wait_scan after all other kernel modules to ensure that
all SCSI device nodes have been created.
* Increase the timeout for the appearance of the root device to 20
seconds.
* Do a "udevadm settle" just after the root device has appeared to
make sure that udev isn't accessing the device anymore (hopefully).
On EC2 (Xen), I've seen fsck on the root fail randomly with "device
in use" errors.
svn path=/nixos/trunk/; revision=33650
I set it as default because users can benefit of this without having to prepare
their nixos first, and I don't think it will break any nixos for the initrd
size increase.
It can be disabled with 'boot.initrd.withExtraTools = false'.
svn path=/nixos/trunk/; revision=33000
possibility that a udevd process survives, preventing udevd from
starting in stage 2:
machine# udevd[1421]: bind failed: Address already in use
machine# udevd[1421]: error binding udev control socket
svn path=/nixos/trunk/; revision=29434
root=... kernel command line parameter, instead of hard-coding it in
`fileSystems'. This is to allow CD-to-USB converters such as
UNetbootin to rewrite the kernel command line to the label or UUID
of the USB stick.
svn path=/nixos/trunk/; revision=23024
we want to generate the GRUB menu without actually installing GRUB
(because Amazon supplies its own pv-grub), and each menu entry
requires "root (hd0)". For the first, allow boot.loader.grub.device
to be set to "nodev" to indicate that the GRUB menu should be
generated without installing GRUB. For the second, add an option
boot.loader.grub.extraPerEntryConfig to allow commands to be added
to each GRUB menu entry (in this case, "root (hd0)").
svn path=/nixos/trunk/; revision=22712
to use the standard (coreutils) tools.
* Use util-linux's `switch_root' to switch over to the target root
FS. It automatically moves over the /dev, /proc and /sys from stage
1, so stage 2 doesn't need to set them up again.
svn path=/nixos/trunk/; revision=22085