[Bug 1731566] Re: systemd-udevd delays boot for 4+ minutes when an LVM PV is inside an LV

[Metta Crawler]

Re: But the inner PV is only for the guest to use - no?

The intent is that the inner PV is only for the guest to use.  What has
happened for years and years is that unless you mask using
/etc/lvm/lvm.conf the host will vgscan the inner PV and vgchange it too.
Until 17.10 (possibly 17.04, I skipped that one) this was mostly a
cosmetic issue, now it adds four minutes to the boot time.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1731566

Title:
  systemd-udevd delays boot for 4+ minutes when an LVM PV is inside an
  LV

Status in systemd package in Ubuntu:
  New
Status in udev package in Debian:
  New

Bug description:
  $ lsb_release -rd
  Description:	Ubuntu 17.10
  Release:	17.10

  $ apt-cache policy udev
  udev:
    Installed: 234-2ubuntu12.1
    Candidate: 234-2ubuntu12.1
    Version table:
   *** 234-2ubuntu12.1 500
          500 http://us.archive.ubuntu.com/ubuntu artful-updates/main amd64 Packages
          500 http://security.ubuntu.com/ubuntu artful-security/main amd64 Packages
          100 /var/lib/dpkg/status
       234-2ubuntu12 500
          500 http://us.archive.ubuntu.com/ubuntu artful/main amd64 Packages

  Expected:

  Ubuntu 17.10 booting up as fast as Ubuntu 16.04

  What happened instead:

  During boot up the system will hang and then a timeout will allow it
  continue. This happens twice.

  The first one occurs right after the network interfaces are renamed. Example:
  [    5.160480] e1000e 0000:02:00.0 enp2s0f0: renamed from eth0
  [  121.345255] raid6: sse2x1   gen()  4431 MB/s

  The second one is from /scripts/init-bottom/lvm where 'udevadm
  --settle' is run.

  # we cannot properly synthesize LVM LV change events with udevadm trigger, so
  # if we use LVM, we need to let it finish; otherwise we get missing LV symlinks
  # (LP #1185394)
  if [ -x /sbin/vgchange ]; then
      udevadm settle --timeout=121 || true
  fi

  Reproducing:

  Where $vg is some existing volume group name:

  lvcreate -n pvtest -L 20m $vg
  pvcreate /dev/$vg/pvtest
  reboot

  Use case:

  KVM/Qemu libvirt VM guest's vda with PV in it stored in host LV.
  This is somewhat involuntary as certain appliance VMs come configured this way.

  ProblemType: Bug
  DistroRelease: Ubuntu 17.10
  Package: udev 234-2ubuntu12.1
  ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4
  Uname: Linux 4.13.0-16-generic x86_64
  ApportVersion: 2.20.7-0ubuntu3.1
  Architecture: amd64
  CurrentDesktop: ubuntu:GNOME
  Date: Fri Nov 10 18:29:33 2017
  InstallationDate: Installed on 2017-11-05 (5 days ago)
  InstallationMedia: Ubuntu-Server 17.10 "Artful Aardvark" - Release amd64 (20171017.1)
  MachineType: System manufacturer System Product Name
  ProcEnviron:
   TERM=xterm-256color
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.13.0-16-generic root=/dev/mapper/vg1-root ro verbose
  SourcePackage: systemd
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 07/05/2012
  dmi.bios.vendor: American Megatrends Inc.
  dmi.bios.version: 3029
  dmi.board.asset.tag: To Be Filled By O.E.M.
  dmi.board.name: M4A89GTD-PRO/USB3
  dmi.board.vendor: ASUSTeK Computer INC.
  dmi.board.version: Rev 1.xx
  dmi.chassis.asset.tag: Asset-1234567890
  dmi.chassis.type: 3
  dmi.chassis.vendor: Chassis Manufacture
  dmi.chassis.version: Chassis Version
  dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr3029:bd07/05/2012:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnM4A89GTD-PRO/USB3:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
  dmi.product.family: To Be Filled By O.E.M.
  dmi.product.name: System Product Name
  dmi.product.version: System Version
  dmi.sys.vendor: System manufacturer

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1731566/+subscriptions