The host id value gets generated by reading a 32-bit value from
/dev/urandom.
This makes programs that rely on a correct host id more reliable.
It also makes using ZFS more seamless, as you don't need to configure
the hostId manually; instead, it becomes part of your config from the
moment you install NixOS.
The old boot.spl.hostid option was not working correctly due to an
upstream bug.
Instead, now we will create the /etc/hostid file so that all applications
(including the ZFS kernel modules, ZFS user-space applications and other
unrelated programs) pick-up the same system-wide host id. Note that glibc
(and by extension, the `hostid` program) also respect the host id configured in
/etc/hostid, if it exists.
The hostid option is now mandatory when using ZFS because otherwise, ZFS will
require you to force-import your ZFS pools if you want to use them, which is
undesirable because it disables some of the checks that ZFS does to make sure it
is safe to import a ZFS pool.
The /etc/hostid file must also exist when booting the initrd, before the SPL
kernel module is loaded, so that ZFS picks up the hostid correctly.
The complexity in creating the /etc/hostid file is due to having to
write the host ID as a 32-bit binary value, taking into account the
endianness of the machine, while using only shell commands and/or simple
utilities (to avoid exploding the size of the initrd).
This changes the bootloader for iso generation from Grub to
syslinux. In addition this adds USB booting support, so that
"dd" can be used to burn the generated ISO to USB thumbdrives
instead of needing applications like UnetBootin.
This reverts commit 469f22d717, reversing
changes made to 0078bc5d8f.
Conflicts:
nixos/modules/installer/tools/nixos-generate-config.pl
nixos/modules/system/boot/loader/grub/install-grub.pl
nixos/release.nix
nixos/tests/installer.nix
I tried to keep apparently-safe code in conflicts.
Should bring most of the examples into a better consistency regarding
syntactic representation in the manual.
Thanks to @devhell for reporting.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
On some non-NixOS systems (for example those using "resolvconf"),
/etc/resolv.conf is a symlink. So let's dereference when copying hasts
and resolv.conf.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
An escape char is needed to prevent "$ nix" from being evaluated and
expanded to an empty string. With this change the resulting text is
$ nix-env -qaP | grep wget
instead of
-env -qaP | grep wget
When formatting a nixos usb using my windows machine I noticed that the
disk labeling using periods was not compatible with my linux kernel /
udev recognition. When labeling a volume NIXOS_14.10 under Windows, it would
show up as NIXOS_14_10 on NixOS. This meant that /dev/root would never come
up at boot time, preventing the livecd from starting.
This patch works around this issue by eliminating any special characters
other than underscores. The previous versioning didn't seem all that
useful, especially when consdering there are many different version of
the year.month named iso.
