The Disk Usage control provides a summary of storage space used by your Institution, and the selected Organization and Library. If there is a Disk Quota set at any of these levels, a graphic will also show storage used against the Quota.
To view disk usage for a library, organization, or institution, click Administration in the navigation column, then click Library and select Disk Usage.
In the example above, we're logged in using a Contributor account, so we can only see disk usage for this Library. An Organization Administrator will also see disk usage for the current Organization, and an Institutional Administrator will also see usage for the Institution.
Administrators: To manage the Disk Quota for a Library, see the Managing Libraries guide.