Sometime I need some additional disks or volume groups to do some testing. E.g. it’s widely used for OpenStack Cinder testing with LVM driver.
Usually, I don’t have additional disks to work with:(. That’s why I use loopback devices instead. It’s an easy to configure solution. Of course, it works a but slower than on a real hardware but it’s absolutely acceptable for many scenarios.
I’ll show you an example based on Devstack solution.
There are only three steps to do it.
Create backing file to store your data:
sudo dd if=/dev/zero of=/opt/fake-lvm bs=1M count=20480- it will create a 20Gb file filled with zeros.Create new loopback device
sudo losetup -f --show /opt/fake-lvm- this command returns a new loopback device name like/dev/loopNAfter this, you can create partitions and filesystems using
fdiskandmkfsutilities or new volume group viasudo vgcreate test-vg /dev/loopNcommand
More information about losetup you can find in
man