You may perform resizing of disk attached to an edge server or a storage server using CP.
During resizing, the storage server will be turned off. If the file is currently cached in edge server, user will be able to get the cached/stale content. However if the file is yet cached in the edge server, the user will see 502 or 504 error.
After the completion of successful disk resizing, the server will be turned on automatically.
If you wish to know the filesystem size limit, kindly refer to the following KB: