17 Long-term data retention in the Digital Age For several generations of storage professionals, tape backup has been the IT equivalent of Sisyphus forever pushing a huge boulder up a hill. It still is. Despite vendors’ best efforts to innovate, data quantities always seem to grow faster than tape capacity. This is truer than ever today. Digital Business is driving an exponential expansion of data volumes, to the point where the average backup hovers at around a petabyte. The trouble with tape backup. How about an alternate scenario: Eliminate tape drives and offsite rotation completely, and archive data on disk drives instead. Many IT leaders and analysts believe this is an idea whose time has come. An important motivator is tape reliability, or rather the lack of it. Tape drives have lots of complex moving parts which can and do break. There are numerous starts and stops as the data stream from the backup server ebbs and flows. Drives are also susceptible to airborne dust and grit. All this wear and tear takes a toll. Industry analysts have long noted that tape backups fail as much as 50% of the time, bogging down storage techs with hours of troubleshooting on a regular basis. Opinions vary on the longevity of the tape medium itself, but the shelf life of stored information is surprisingly limited. Tape-archived data can be corrupted by the earth’s magnetic field, oxidation, and electromagnetic radiation from other devices. The general rule of thumb for tape is no more than 2 or 3 years of data durability. Another downside is access latency, as tape drives can take several minutes to load, mount, and position before a single byte can be read. There are also hassles and security risks that come with manually handling tapes. Tape’s prime selling point has always been price. However, disk density has gone up, and prices down, to the point where disks are competitive with tape on a cost-per-TB basis, especially at high capacities. On top of this, the greater efficiency of disk per unit of storage may tip the scales in its favor. Thanks to data deduplication and replication, disk backups can be limited to each day’s or week’s new and altered data, rather than having to repeatedly archive the entire store, just to capture the 3% that’s new or changed since the last run. These tape drawbacks have not gone unnoticed. As reported in TechTarget, an ESG survey of several hundred North American storage professionals shows that a significant tape replacement cycle has begun: 76% of users have switched from tape libraries to disk storage, or are looking to do so. Some enterprises are considering cloud-based “backup-as-a-service” options. Others feel their archived data is too sensitive to store externally, even if encrypted. Across industries, the search is on for an architecture that combines the benefits of disk and cloud backup with the economic advantages of tape. To compete, such an option would have to combine affordability with higher reliability and faster data access than tape. It would also need enterprise-class security. Network Attached Storage (NAS) doesn’t fill the bill. It’s limited to maybe a few petabytes and entails considerable networking complexity. Most critically, the price tag for proprietary NAS servers and appliances is cost-prohibitive at scale. More than a few enterprises have discovered an ideal solution: the Scality RING software-defined object storage platform. Operating on low-cost industry-standard x86 servers, the RING pools storage resources for much higher efficiency than other alternatives. For even greater economies of scale, the RING lets you consolidate archiving for multiple sites, saving the cost of maintaining separate libraries for each. The RING satisfied all the other tape-replacement criteria, too. All in all, it lets you build exabyte-scale active archives with all the performance benefits of disk, at a price point comparable to tape—perfect for retention of backups for restore, auditing, and compliance purposes.
