There can be many reasons why a magnetic tape cannot be read; some of the issues can be temporary and others are...
more permanent. Some tape errors can be attributed to operational or pilot error or mishandling, while other errors can be the result of damaged media or tape drives.
Below are some reasons you may encounter tape errors:
- Heat, smoke, fire and water damage
- Damaged or broken tapes and cartridges
- Accidental deletion or overwritten data and reformatted tapes
- Tape drive and other mechanical wear and tear
- Dirty tape drives
- Lack of proper tape storage and handling
- Exceeding manufacturer suggested lifetime of the media
- What errors are being logged by your tape drive when you try to read the tape?
- Does the error occur if you try reading the tape on a different tape drive?
- Are other tapes readable on the same tape drive using the same utilities?
- Is there any obvious physical or visible damage to the tape media or cartridge?
- Are you able to read the tape from a different server?
- Is the tape encrypted or compressed, thus preventing the media from being read?
- Has the tape media been properly acclimated if recently moved or transported?
- Is there visible physical damage to the tape drive device?
A first step should be to check with your technology provider, or the vendor who sold you (and provides the servicing for) your tape drive. Some vendors have Web sites that list frequently asked questions and other troubleshooting tips that may help your diagnose your tape errors.
There are several firms providing services for recovering data from damaged or corrupted tapes. While this list isn't complete, a few companies that provide these services include: Imation, Quantum, Exabyte, Sun/STK, HP and IBM, among others.
In 2003, for example, after the tragic Columbia space shuttle disaster, technicians at Imation along with NASA and other experts, were able to recover critical data from the severally damaged flight data recorder tapes of the stricken space shuttle to support the accident investigation.
There are specialty firms that deal with recovery of media from disk and/or tape as well as optical media. A Google search of the phrase "tape media recovery" will yield a list of different service providers that may meet your specific needs. Inquire if the vendor provides physical as well as logical (data) recovery of damaged media or if an external third party is involved in the process. Look for a recovery service provider that has experience and credibility in recovering damaged media matching your needs and requirements. For example, be familiar with which tape formats, type of tape drives, operating system and applications or backup utilities and data formats are they familiar with. Since critical and sensitive private data will reside on your tape media, look into and ask a service provider about their security and privacy policies -- including who will have access to the media and any recovered data.
To help minimize the chance of damaging tapes, exercise caution and follow manufacturer suggested best practices for tape handling and media storage. In addition, periodically and randomly audit and test tapes along with your data protection and archiving to tape media processes. As part of an audit, verify that the correct data is stored on the media and that it can be restored. Another safeguard is to test the restoration using a different tape drive to an alternate location to verify that the tape is good. Also, test and verify that your backup or archiving application parameter settings and configurations are correct as you intended. For critical data, make an alternate copy of the data on the same or different type of media and store in a climate controlled environment to minimize lost data.
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About the author: Greg Schulz is founder and senior analyst with the IT infrastructure analyst and consulting firm StorageIO. Greg is also the author and illustrator of "Resilient Storage Networks" (Elsevier) and has contributed material to "Storage" magazine and other TechTarget venues.