LVM: remove PV from VG

#
# Create test LV
#
for i in {1..3}; do
    truncate -s 1G disk${i}.img
    losetup /dev/loop${i} disk${i}.img
    pvcreate /dev/loop${i}
done

pvs

vgcreate vg0 /dev/loop1 /dev/loop2 /dev/loop3

vgs

lvcreate -n lv0 -l 100%FREE vg0

lvs

mkfs.ext4 /dev/vg0/lv0

mount /dev/vg0/lv0 /mnt/

df -h /mnt/

for i in {1..15}; do
    dd if=/dev/urandom of=/mnt/file${i} bs=1M count=100
done

md5sum /mnt/file? > /mnt/file.md5

(cd /mnt && md5sum -c file.md5)


#
# Reduce LV and remove PV from VG
#
umount /mnt/

#e2fsck -f -v -C 0 /dev/vg0/lv0
e2fsck -f /dev/vg0/lv0

resize2fs /dev/vg0/lv0 1800M

lvreduce -L 1900M /dev/vg0/lv0
vgs

vgreduce vg0 /dev/loop3

vgs
pvs

pvremove /dev/loop3
pvs



#
# Check filesystem
#
mount /dev/vg0/lv0 /mnt/
(cd /mnt && md5sum -c file.md5)
umount /mnt/

# Links
https://www.centos.org/docs/5/html/Cluster_Logical_Volume_Manager/VG_remove_PV.html
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/logical_volume_manager_administration/vg_remove_pv