Bug 1378612

Description of problem:

Placing into /etc/lvm/lvmlocal.conf:

global {
    use_lvmetad = 0
}

entirely breaks activation of the LVM volumes, resulting in various boot problems.

Version-Release number of selected component (if applicable):

LVM TOOLS 2.02.165(2) (2016-09-07) and earlier, backported to the Debian 8.6 Jessie.

How reproducible:

Since recent enough versions of LVM2 support additional local configuration files like /etc/lvm/lvmlocal.conf and earlier versions supported tagged additional configs, like /etc/lvm/lvm_drbd.conf I use those options to put desired changes into separate files to ease maintainance and upgrades of the LVM.

This approach used to work fine, in particular with my DRBD/LVM/NFS cluster setup where some minimal changes were placed into lvm_drbd.conf(and later into lvmlocal.conf):

devices {
    global_filter = [ "a|^/dev/sd.*|", "a|^/dev/drbd.*|", "r|.*|"  ]
    write_cache_state = 0
}

activation {
    volume_list = [ "vg00", "store0", "share0" ]
}

Latest versions of LVM2 resource script for pacemaker started to complain about use of use_lvmetad=1, suggesting to disable it. So, lvmlocal.conf got additional:

global {
    use_lvmetad = 0
}

And that lead to the failure of volumes activation. That's possibly was made worse by my attempt to bring consistency to the content of /etc/lvm/ in a live system and initrd.

Current mkinitramfs LVM2 script(at least on Debian) copies only /etc/lvm/lvm.conf to the resulting image, skipping rest of lvm*.conf files, which may alter the final configuration.

I've added /etc/initramfs-tools/hooks/lvm2-local script to work around this:
#!/bin/sh

PREREQ="lvm2"

prereqs()
{
  echo "$PREREQ"
}

case $1 in
prereqs)
  prereqs
  exit 0
  ;;
esac

. /usr/share/initramfs-tools/hook-functions

# command profile config -> metadata profile config -> tag config -> lvmlocal.conf -> lvm.conf
if [ -d /etc/lvm/ ]; then
  mkdir -p ${DESTDIR}/etc/lvm
  cp /etc/lvm/lvm*.conf ${DESTDIR}/etc/lvm/
fi

So, now I get consistent behvior of LVM2 during initrd stage and the normal boot.

Steps to Reproduce:
1. Place into /etc/lvm/lvmlocal.conf:
global {
    use_lvmetad = 0
}

and make sure that it is also copied into initrd image. LVM in initrd image reads all available config files and doesn't try to use lvmetad(actually, with use_lvmetad=1 it complains that can't access lvmetad and does direct read of meta info).

2. Make sure that initrd is updated and contains all lvm*.conf files.

3. Reboot

Actual results:

# lvs -a
  LV   VG   Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  opt  vg00 -wi------- 16.00g

# systemctl status lvm2-activation.service
● lvm2-activation.service
   Loaded: not-found (Reason: No such file or directory)
   Active: inactive (dead)

Expected results:

# lvs -a
File descriptor 7 (pipe:[15440]) leaked on lvs invocation. Parent PID 796: bash
  LV   VG   Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  opt  vg00 -wi-a----- 16.00g

# systemctl status lvm2-activation.service
● lvm2-activation.service - Activation of LVM2 logical volumes
   Loaded: loaded (/etc/lvm/lvm.conf)
   Active: inactive (dead) since Fri 2016-09-23 01:02:30 CEST; 2min 58s ago
     Docs: man:lvm2-activation-generator(8)
  Process: 390 ExecStart=/sbin/lvm vgchange -aay --ignoreskippedcluster (code=exited, status=0/SUCCESS)
 Main PID: 390 (code=exited, status=0/SUCCESS)

Sep 23 01:02:30 exp01.ad-lab.nl lvm[390]: 1 logical volume(s) in volume group "vg00" now active
Sep 23 01:02:30 exp01.ad-lab.nl systemd[1]: Started Activation of LVM2 logical volumes.

Additional info:

# strace -ff -o /tmp/lvm2 /lib/systemd/system-generators/lvm2-activation-generator /var/tmp /var/tmp /var/tmp

Reveals, that lvm2-activation-generator reads only lvm.conf:
open("/proc/filesystems", O_RDONLY)     = 3
fstat(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f392d855000
read(3, "nodev\tsysfs\nnodev\trootfs\nnodev\tr"..., 1024) = 311
read(3, "", 1024)                       = 0
close(3)                                = 0
munmap(0x7f392d855000, 4096)            = 0
open("/dev/kmsg", O_WRONLY|O_NOCTTY)    = 3
stat("/etc/lvm/lvm.conf", {st_mode=S_IFREG|0644, st_size=93207, ...}) = 0
stat("/etc/lvm/lvm.conf", {st_mode=S_IFREG|0644, st_size=93207, ...}) = 0
open("/etc/lvm/lvm.conf", O_RDONLY)     = 4
mmap(NULL, 93207, PROT_READ, MAP_PRIVATE, 4, 0) = 0x7f392d82f000
munmap(0x7f392d82f000, 93207)           = 0
close(4)                                = 0
stat("/etc/lvm/lvm.conf", {st_mode=S_IFREG|0644, st_size=93207, ...}) = 0
stat("/etc/lvm/lvm.conf", {st_mode=S_IFREG|0644, st_size=93207, ...}) = 0
open("/etc/lvm/lvm.conf", O_RDONLY)     = 4
mmap(NULL, 93207, PROT_READ, MAP_PRIVATE, 4, 0) = 0x7f392d82f000
munmap(0x7f392d82f000, 93207)           = 0
close(4)                                = 0
close(3)                                = 0

Without checking other additional configuraton files, which makes it inconsistent with lvm tool(and friends).

Placing global/use_lvmetad=0 into /etc/lvm/lvm.conf makes it work as desired, generating appropriate set of lvm2-activation-early.service  lvm2-activation-net.service  lvm2-activation.service

So, can it be extended to read the same set of configuration files as the rest of utils do?