According to Calamares' session.log of the failed installation it seems that Calamares deactivates/closes the volume group just before trying to mount it as the install target - which thus can't work. There is already an upstream bug report about that behaviour that I'll link here (currently closed, yet there is recent activity of people still experiencing this kind of problem).
** Bug watch added: Calamares Issues #1564 https://github.com/calamares/calamares/issues/1564 ** Also affects: calamares via https://github.com/calamares/calamares/issues/1564 Importance: Unknown Status: Unknown -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2061123 Title: Calamares fails to install on logical volume if no partition/LV is marked for being formatted To manage notifications about this bug go to: https://bugs.launchpad.net/calamares/+bug/2061123/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
