LVM Setup

Linux mount an LVM volume / partition command
How to Manage and Create LVM Using vgcreate, lvcreate and lvextend Commands
CentOS / RHEL : How to find Logical volumes (LVs) contained in Physical Volume (PVs) in LVM
System Manager’s Manual PVMOVE(8)
Physical Extents

not to much useful

Logical Volume Administration
Creating an LVM volume group and logical volume on the hypervisor host

How to shrink a physical volume?

How to shrink a physical volume?

Recovering a failed software RAID
Missing mdadm raid5 array reassembles as raid0 after powerout

Stop Raid

systemctl stop urbackupsrv
umount /dev/md0
mdadm –stop /dev/md0
dd if=/dev/sdd1 of=/mnt/Data/raidbackup.img