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Logical Volume Manager su Linux

Come usare LVM per gestire lo storage in modo flessibile: estendere partizioni, aggiungere dischi e creare snapshot.

1. Concetti base

• PV (Physical Volume): disco fisico o partizione
• VG (Volume Group): insieme di PV
• LV (Logical Volume): partizione logica dentro un VG

2. Creare un volume LVM da zero

pvcreate /dev/sdb
vgcreate vg-data /dev/sdb
lvcreate -l 80%VG -n lv-storage vg-data
mkfs.ext4 /dev/vg-data/lv-storage
mkdir /mnt/storage
mount /dev/vg-data/lv-storage /mnt/storage

3. Estendere un volume esistente

pvcreate /dev/sdc
vgextend vg-data /dev/sdc
lvextend -L +100G /dev/vg-data/lv-storage
resize2fs /dev/vg-data/lv-storage

4. Snapshot LVM

lvcreate -s -n snap-storage -L 1G /dev/vg-data/lv-storage
mount -o ro /dev/vg-data/snap-storage /mnt/snapshot
lvconvert --merge /dev/vg-data/snap-storage

5. Comandi di monitoraggio

pvs     # Lista Physical Volumes
vgs     # Lista Volume Groups
lvs     # Lista Logical Volumes

Risultato: Storage flessibile con LVM — estensione a caldo, snapshot e gestione multi-disco.