kernel 3.4+ needs cifs-utils to mount CIFS filesystems.
the kernel itself (and busybox's cifs mount code) are no longer able
to do this in some/most cases and will error out saying:
"CIFS VFS: connecting to DFS root not implemented yet"
Nixos' qemu-vm target is hurt by this, as it wants to mount /nix/store
via cifs very early in the boot process.
This commit makes sure the initrd for affected kernels is built with
cifs-utils if needed.
We had a "mount -o remount,rw none /" that was setting back 'relatime',
although we had set 'noatime' at initrd mount. Removing the word 'none' fixed
it.
Specifying a device (in this case 'none'), makes mount to forget previous
device options. According to manpage, it says not to read fstab or mtab. But the
effect is that of setting 'relatime', if it was mounted 'noatime.
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).
Upstart requires /dev/ptmx since its 1.4, and will lock up in case of it missing.
I was hitting this in the fuloong, where I don't use the nixos initrd.
svn path=/nixos/trunk/; revision=34429
* 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
* Add a slash to the end of $MODULE_DIR, as expected by depmod. (Not
that running depmod from the command line is all that useful, since
you can't use it to update the tree in the Nix store. But at least
commands like "depmod -n" work now.) Reported by Kirill Elagin on
IRC.
svn path=/nixos/trunk/; revision=33312
