To reduce the disc size of the CentOS 6 virtual machine, you need to use the old version of vCloud Director based on Flash. To access the Flash interface, it is necessary to add your company name to the link https://vcd.cloud4u.com/cloud/org/ in the way specified in the FLASH interface. For example, https://vcd.cloud4u.com/tenant/org-name получается https://vcd.cloud4u.com/cloud/org/org-name
1. Add a data transfer disc (smaller size). Change the boot order using Unit Number, as shown in the picture.
2. Boot the system from the iso image of Clonezilla Live. On the menu that is shown in the picture, select Enter command line prompt.
3. Type sudo su root, then fdisk -l to define disk names. Copy part of the working disk from the first sector along the border of the boot partition to a new one. 
4. Correct the partition table on the new disc using fdisk /dev/sda. To do this, delete all partitions except the first, then select all free space for a partition of type LVM (8e).
5. Define the name of the volume group, convert the created partition to a physical volume and expand the required group.
6. Find out the name of the decreasing logical volume, check the file system on it, and reduce its size a bit more than planned.
7. Reduce the logical volume, align the file system size and check again.
8. Transfer data to the new physical volume and remove the vacant volume from the group.
9. Turn off the system and remove the original disk.
