Through the NFR Agent, Novell® File Reporter takes a “scan” of the file system of the storage resource at the moment it is examined. The scan includes comprehensive information on file types being stored, if these files are duplicated, where duplicate files reside, when files were created, when files were last opened, and more.
While the scan is being conducted, the data for the scan is stored on the server hosting the NFR Agent. After the scan is completed, the data is compressed and transferred to the server hosting the NFR Engine.
Scans are indexed and compressed data that is specific to a storage resource. Scans are decompressed only when data within the scan is used to generate a report. In other words, a scan of a particular storage resource is utilized only if it includes content that is part of the specifications of a report request. For example, if an administrator runs a report specific to user home directories, and all of those directories are located on two volumes, the scans that the administrator uses to generate the report are only the scans from the two specific volumes, and not scans from the other storage resources.
Scans are both indexed and compressed because of their potentially large size. Indexing means that certain data—such as a file owner’s name—is stored just once in the index, with pointers to all files owned by that user. Additionally, the scan is compressed. By using both indexing and compression, the scan is stored at a fraction of its actual size. For example, a decompressed scan of a single storage resource with 12,000,000 files is 1.44 GB. Indexed and compressed, the scan is 464 MB.
Scans can be taken at any time, but we recommend using a scheduled time after normal business hours to minimize the effect on network performance.
You should consider a number of factors as you decide how often to conduct a scan:
Although daily scanning always provides the most up-to-date information, scanning is not throttled and places a considerable load on the server hosting the NFR Agent.
Most storage resources do not change rapidly enough to justify daily scanning.
Monthly scanning places the least total load on individual servers and on the network, but scans are not as up-to-date as they could be.
You can scan frequently changing volumes more often and scan the more static volumes less often.
Part of the decision concerning scanning frequency involves the primary purpose of the reporting. Reporting on storage trending can generally use less frequent scans, but reporting that’s intended to solve immediate problems, such as “Who filled up this volume?” needs more frequent scans.
When information is needed immediately, you can manually trigger a scan.
For installations where you’re not sure of the optimal scanning frequency, you can start with weekly scanning, and then adjust that interval based on the needs of the particular site.