Below you find a solution if you want to make a LVM Snapshot before you install the latest Updates.
Table of contents
1. Environment
2. Create a Snapshot before you install the latest Update
3. If the Updates don’t break your system
4. If the Updates break you system
1. Environment
Partition table
sudo fdisk -l /dev/sda
Disk /dev/sda: 40 GiB, 42949672960 bytes, 83886080 sectors
Disk model: QEMU HARDDISK
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x3a11f056
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 1230847 1228800 600M 83 Linux
/dev/sda2 1230848 83886079 82655232 39.4G 8e Linux LVMLVM
sudo pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 vg_root lvm2 a-- 39.41g 0
sudo vgs
VG #PV #LV #SN Attr VSize VFree
vg_root 1 2 0 wz--n- 39.41g 10.00g
sudo lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv_root vg_root -wi-ao---- 25.41g
lv_swap vg_root -wi-ao---- 4.00g 2. Create a Snapshot before you install the latest Update
sudo lvcreate --extents 100%FREE --snapshot --name lv_root_snap /dev/mapper/vg_root-lv_root
Logical volume "lv_root_snap" created.
sudo lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv_root vg_root owi-aos--- 25.41g
lv_root_snap vg_root swi-a-s--- 10.00g lv_root 0.01
lv_swap vg_root -wi-ao---- 4.00gNow you can update your system
3. If the Updates don't break your system
You can remove the Snaphost with the following command
sudo lvremove vg_root/lv_root_snap4. If the Updates break you system
Use the commands below if the Updates break your system. It’s possible to run this command when your system boots normally or from a Live System.
sudo lvconvert --merge vg_root/lv_root_snap
sudo reboot
sudo lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv_root vg_root Owi-aos--- 25.41g 1.42
lv_swap vg_root -wi-ao---- 4.00g Now the Snapshot merge with the main lv in the background. If it is down to 0% you can reboot your system.