When Site Collections and Sites are created in MS SharePoint the administrator defines a certain storage space. As users start using the site intensively and upload a lot of large documents, the site can run out of space. The SharePoint Administrators receive many e-mails and calls relating to storage issues.  

This is why Ometa developed the Storage Web Part. 

With the storage Web Part the users can see the real-time storage usage of their sites.  Bigger quota can be asked well in advance or users can start cleaning up the site. 

The Web Part shows the storage size in a graphical toolbar at the top and in a more detailed table view underneath.  

Below you can see an example of how the Web Part looks like. 

The graphical toolbar always shows the storage size on site collection level, for the table view it depends. If the Ometa Web Part is configured on site collection level, it shows the complete site collection, if it is configured on site level it shows only details from the site.