then reboot. The volume vg0/home_lv_root disappears.
I try to find it:
pvscan
vgscan
lvscan
vgchange -ay
The vgchange complains it cannot complete "cache_check".
Here lies the problem: /usr/sbin/cache_check is in thin-provisioning-tools
So without thin-provisioning-tools it is possible to create an LVM2 volume which disappears on reboot.
This suggests that thin-provisioning-tools must be a prerequisite, or that cache_check be moved into package lvm2.
This also appears to be related to bug #1423796, if an LVM volume has a cache attached and is required at boot time, boot will fail completely. Creating a cached root volume seemed like a sensible thing to do. This also occurred to me today on a server config, and I moved the OS entirely onto an SSD partition rather than deal with it.
This is related to a problem I've encountered today with lvmcache partitions.
From a fresh Ubuntu 18.04 install, with lvm2 installed, I create an LVM on HDD's with an SSD partitioned to provide cache:
lvcreate -n home_lv_root -L 1.2Tb vg0 lv_cachemeta \
vg0/home_ lv_cache
vgextend vg0 /dev/nvme0n1p6
lvcreate -n home_lv_cache -L 17G vg0 /dev/nvme0n1p6
lvcreate -n home_lv_cachemeta -L 1.6G vg0 /dev/nvme0n1p6
lvconvert --type cache-pool --poolmetadata vg0/home_
lvconvert --type cache --cachepool vg0/home_lv_cache vg0/home_lv_root
then reboot. The volume vg0/home_lv_root disappears.
I try to find it:
pvscan
vgscan
lvscan
vgchange -ay
The vgchange complains it cannot complete "cache_check".
Here lies the problem: /usr/sbin/ cache_check is in thin-provisioni ng-tools
So without thin-provisioni ng-tools it is possible to create an LVM2 volume which disappears on reboot.
This suggests that thin-provisioni ng-tools must be a prerequisite, or that cache_check be moved into package lvm2.
This also appears to be related to bug #1423796, if an LVM volume has a cache attached and is required at boot time, boot will fail completely. Creating a cached root volume seemed like a sensible thing to do. This also occurred to me today on a server config, and I moved the OS entirely onto an SSD partition rather than deal with it.