The fact that we always write data exclusively on two different tape cartridges in two completely independent tape libraries, offers protection against unforeseen disruptions.
With aging, however, is a small probability that both copies are affected by errors. Therefore, our test procedures in a long-term preservation is essential.
With all these considerations, one should not forget that the hardware compression on the tape drives performed well so 2TB, but at least 1TB of data fit on a single cartridge.
Ensuring the readability of tape material
Considerable effort, we operate to ensure the readability of tapes after perhaps years of storage without use. Even without the use of the tapes are subject to an aging process (physical deterioration) that can eventually cause serious problems or a complete failure
First, we have installed a monitor that continuously records the diagnosis of the drives that would normally be done for maintenance purposes. We capture and evaluate this information automated. We even get information about any problems that were never reported because of irrelevance to the server as an error. However, we can use this information to assess the quality of the tapes and impending problems early on.
According to our threshold values an alarm is set so that we can assess the problem and take any appropriate action.
The problem of assessing the quality of used tapes not long now we have achieved in that we read such tapes for automated sample, without a care for the information contained therein.
If an aging or wear and tear has affected the quality of the tape, recognize our special monitoring this and alerted us. We then decide to manually determine whether to grant further observation or a proactive copying the tape to a new one.