Today I fixed an unbootable ubuntu installation: it said:<\/p>\n
lvmetad is not active yet<\/p><\/blockquote>\n
It then dumped to an initramfs<\/em> shell, in which
lvm pvs<\/code> reported nothing but errors.\u00a0\/proc\/partitions<\/code> showed nothing that looked like the root filesystem. Runningudevadm trigger<\/code> produced the following response:<\/p>\nudevadm trigger is not permitted while udev is unconfigured<\/p><\/blockquote>\n
However, nothing explained why udev<\/strong> was unconfigured.<\/p>\n
The cause of this is that the udev<\/strong> package contains a wrapper script for udevadm<\/strong> which is supposed to exist only during the installation of udev<\/strong>.\u00a0 This script is not actually capable of doing anything, but stops udevadm<\/strong> messing things up during an upgrade.<\/p>\n
When udev<\/strong> remains unconfigured at the time that update-initrd<\/strong> is run, then the generated initrd<\/strong> image contains a copy of a non-working udevadm<\/strong> command.\u00a0 This command cannot be used to activate user devices, and so things like hard disks, partitions, filesystem and LVM partitions fail to exist.\u00a0 The boot loader could not find its LVM, because it couldn’t find the device that the LVM is on, because it didn’t load the driver for the controller for that device.<\/p>\n
The fix is to help the udevadm<\/strong> upgrade to complete (or at least not be totally broken), and then re-generate the initramfs<\/strong> with working code:<\/p>\n
root@urk:\/bin# cp udevadm.upgrade udevadm<\/strong>\r\n\r\nroot@urk:\/bin# update-initramfs -k all -c<\/strong>\r\nupdate-initramfs: Generating \/boot\/initrd.img-3.13.0-32-generic\r\n\r\nroot@urk:\/bin# apt-get -f install<\/strong>\r\nReading package lists... Done\r\nBuilding dependency tree\r\nReading state information... Done\r\n0 upgraded, 0 newly installed, 0 to remove and 162 not upgraded.\r\n8 not fully installed or removed.\r\nAfter this operation, 0 B of additional disk space will be used.\r\nSetting up udisks2 (2.1.7-1ubuntu1) ...\r\n\/\/ etc\r\n<\/em><\/pre>\nWhen udev<\/strong> is unconfigured, the udevadm <\/strong>script is just a wrapper that says to refuse to run the actions trigger <\/strong>(look for new devices) and settle<\/strong> (wait for existing devices):<\/p>\n
#!\/bin\/sh\r\n\r\nif [ \"$1\" = \"trigger\" ]; then\r\n\u00a0\u00a0\u00a0 echo \"udevadm trigger is not permitted while udev is unconfigured.<\/strong>\" 1>&2\r\n\u00a0\u00a0\u00a0 exit 1\r\nfi\r\n\r\nif [ \"$1\" = \"settle\" ]; then\r\n\u00a0\u00a0\u00a0 echo \"udevadm settle is not permitted while udev is unconfigured.<\/strong>\" 1>&2\r\n\u00a0\u00a0\u00a0 exit 1\r\nfi\r\n\r\nexec \/bin\/bash -c \"exec -a \\\"\\$0\\\" \/bin\/udevadm.upgrade \\\"\\$@\\\"\" \"$0\" \"$@\"\r\n\r\n<\/pre>\nThe fact that the script uses both \/bin\/sh <\/strong>and \/bin\/bash<\/strong> says that it was done without certain types of required forethought.<\/p>\n","protected":false},"excerpt":{"rendered":"
Today I fixed an unbootable ubuntu installation: it said: lvmetad is not active yet It then dumped to an initramfs shell, in which lvm pvs reported nothing but errors.\u00a0 \/proc\/partitions showed nothing that looked like the root filesystem. Running udevadm … Continue reading