LVM thin provisioning

Principle

A thin pool stores shared physical extents; thin volumes advertise virtual capacity that may exceed currently allocated physical storage.

Lab example

sudo lvcreate -L 10G -T vg_lab/pool0
sudo lvcreate -V 20G -T vg_lab/pool0 -n thin0

Monitor

lvs -a -o lv_name,segtype,lv_size,data_percent,metadata_percent vg_lab

Critical warning

Exhausting thin-pool data or metadata can cause I/O errors. Monitor both, set capacity alerts and plan auto-extension. Overprovisioning is not free capacity.