30 seconds boot delay when usr fs is on lvm

[Fabien SK]

A bit similar to "30 seconds boot delay when root fs is on lvm":
https://bugs.launchpad.net/ubuntu/+source/lvm2/+bug/1807499

I installed Kubuntu 19.04 with 2 LVM volume groups (one per disk). My root and my /usr are both located on the same LVM. Mounting /usr takes 30s, but if I move the /usr to a non-LVM partition then the mounting takes no time and the whole boot process is very fast.
In the script "scripts/local" of initramfs-tools, there is a 30s timeout called "slumber" passed to the "wait-for-root" program (from initramfs-tools-bin), and the wait comes from there (I could see it by adding traces before and after). If I decrease the timeout to 10s, the system can still boot correctly (and 20s faster).

I don't know if the problem comes from the initramfs-tools scripts, from wait-for-root or from the integration in (K)Ubuntu.

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: initramfs-tools-core 0.131ubuntu19.2 [modified: usr/share/initramfs-tools/scripts/local]
ProcVersionSignature: Ubuntu 5.0.0-36.39-generic 5.0.21
Uname: Linux 5.0.0-36-generic x86_64
ApportVersion: 2.20.10-0ubuntu27.3
Architecture: amd64
CurrentDesktop: KDE
Date: Tue Nov 19 22:11:18 2019
InstallationDate: Installed on 2017-08-26 (815 days ago)
InstallationMedia: Kubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
PackageArchitecture: all
SourcePackage: initramfs-tools
UpgradeStatus: Upgraded to disco on 2019-08-18 (93 days ago)

[Fabien SK (fabsk)]

I upgraded to Kubuntu 19.10 and the delay disappeared.