Situation: - Stock Centos 4 system with OpenVZ kernel + utilities installed. One big /vz partition, using LVM. Trying to make a backup using: vzdump --dumpdir /var/ --snapshot 101 Error message received: Insufficient free extents (1) in volume group VolGroup00: 16 required What does that mean? It means that you don't have enough free space in the VG (Volume Group) to create an LVM snapshot. What is the solution? Reduce the size of one partition, then resize one LV (logical volume). This is easily done if you don't have only one big / partition. I usually always make a separate partition for /var and for /vz. To determine what logical volume needs to be resized, you can use the df -h command. Mine showed: /dev/mapper/VolGroup00-LogVol05 119G 16G 99G 14% /vz To resize it: Make backups of your VM to be sure Stop the vz service (service vz stop) umount /vz e2fsck -f /dev/VolGroup00/LogVol05 Use resize2fs /dev/VolGroup00/LogVol05 110G Use lvresize to r...