note Before you try this, ensure that the LV isn't in use, for eg, if a VM uses the logical volume, ensure that the VM is shutdown first.
PV is a very useful tool to report progress as DD doesn't report any progress while running. DD on large LVs can take a long time and knowing how long is important, hence PV.
On Debian or Ubuntu
apt-get install pv
yum install pv
note You may need EPEL repository enabled on CentOS first, enable it with,
yum install epel-release
and then try installing PV
In the command below,
Finally we get,
dd if=/dev/vg/lv_img | pv | ssh firstname.lastname@example.org 'gzip --fast > lv_img.gz'