LVM RAID reference

RAID is not a backup

RAID can maintain availability after certain disk failures; it cannot replace independent, tested backups.

Create RAID1 in a lab

sudo lvcreate --type raid1 -m 1 -L 4G -n lv_mirror vg_lab

Inspect health

lvs -a -o lv_name,segtype,lv_health_status,devices vg_lab
watch -n 2 lvs -a -o +devices vg_lab

Notes

A two-copy RAID1 LV needs sufficient distinct physical volumes. Use --alloc policies and inspect placement; test recovery procedures before relying on the design.