Virtualbox take all space for virtual machine

[mazder]

I have virtualbox 3.2.8 with 91 virtual machines, each virtual machine have static hard disk with 20 Gb. There I have ubuntu, windows, mac os x operations systems, each of them takes place no more than 5 Gb. also installed a few programs that take place not more than 1 Gb. So each virtual machine have 14 Gb free space. But in statistic I have that every hard disk of virtual machine takes place 20 Gb. I have 1820 Gb but it must be <600 Gb. Please help me to understand where is other > 1 TB? Thanks..

[Cyberian]

If you chose fixed disk size for your virtual hard disk all of the 20GB are reserved on the host.
In case you chose dynamic disk size euch virtual still might be larger then used space in guest as hard disk aren't filled sequentially.

[mazder]

On server in "/home" directory storied hards disks of all virtual machines. System say - "The volume "home" has only 0 bytes disk space remaining.". This is due to VirtualBox?

[mpack]

91x20GB (fixed) = 1820GB, so basic arithmetic says that alone would fill the drive.

Assuming your "static" meant fixed size that is.

Other things to look for: log files and the use of snapshots.