For many storage administrators, tape is no longer the first media that comes to mind when designing a new backup solution. In most cases, disk has replaced tape media as the primary storage target for many reasons, which include performance, declining cost of disk arrays, reliability of RAID, software options, and the ability to have multiple concurrent data read or write streams that that are not dependent of the number of tape drives available.
That being said, designing a new backup system is not always a rip-and-replace exercise. Unless you wake up one morning and realize you need a solution to back up 50 TB of newly found, never before backed up data, chances are good you have an existing and potentially significant investment in tape technology that you can't necessarily part with that easily. Here some of the reasons why tape technology is still very relevant:
- Not all data is rated with the same criticality level. It is not uncommon to find over half of the systems in a given environment being rated with a recovery time objective (RTO) of 48 hours and beyond. Slower recovery requirements may mean that tape remains a suitable media depending on the type of data.
- The growing concern over power efficiency is highlighting tape as "greener" storage since it consumes no energy while not in use. The robotics and drives in a library do consume energy but usually less than a similar capacity disk array.
- The growing demand for data archives and long-term retention is also creating a reason for many companies to hang on to their tape subsystem as a cost-efficient storage.
Tape technology vendors are continuing to improve and develop the technology, which indicates that there is still strong enough demand for the technology to justify the investment and effort.
IBM's tape libraries
IBM Corp. recently introduced the System Storage TS1130 tape drive. The technology allows storing of up to a TB of data in native format on a single 3592 JB/JX tape media using 1152-track on half-inch tape, and is capable of data rates of 160 MB/sec. The TS1130 is the latest generation of what was once known as 3590 Magstar technology.
IBM has also announced two new expansion frames for the IBM S3500 tape library. Both new models are storage-only expansion frames (no tape drives) and incorporate high-density slot technology, which allows multiple cartridges to be stored in a tiered architecture. The S54 frame is designed to contain up to 1,320 LTO tape cartridges, offering a threefold increase in slot capacity over previous models.
Sun Microsystems Inc./StorageTek
The Sun StorageTek T10000B tape drive can store 1 TB of data in native format (2 TB assuming 2:1 compressing and is capable of data transfer rates up to 120 MB/sec (240 MB/sec with 2:1 compression). The T10000B is also encryption enabled and uses the Sun Crypto Key Management System to manage keys independently of applications and operating platforms.
LTO Ultrium tape format, which is developed jointly by Hewlett-Packard (HP) Co., IBM and Quantum Corp. sold more than 100 million cartridges since the format's inception in September 2000. Two and a half million LTO tape drives have been sold since the inception of the format in 2000, and almost 1 million new drives have shipped since Q3 2006 alone.
With licensing availability announced in January 2008 by the LTO Consortium, we should expect new LTO Generation 5 devices to hit the market shortly. The new generation is capable of storing 3.2 TB of data (assuming a 2:1 compression) and can reach data transfer rates of up to 360 MB/sec (again with 2:1 compression). The LTO roadmap also includes Generation 6 with similar projected capacity and performance increases. No release date has been announced for LTO 6 as of yet.
Continued interest from security minded organizations and growing support from backup software vendors for LTO-4 tape encryption have also contributed to give tape storage a boost. Although native key management is still limited to few backup products among which IBM TSM, it can be expected that other vendors will consider supporting it.
Given the continued efforts and investments from vendors to improve both the performance and capacity of the technology, it is difficult to believe that tape is as dead as some claim. We can expect to have this storage technology to remain popular for some time.
For more on tape libraries and tape encryption, check out Pierre Dorion's Tape encryption FAQ.
About this author: Pierre Dorion is the Data Center Practice Director and a Senior Consultant with Long View Systems Inc. in Phoenix, AZ, specializing in the areas of business continuity and disaster recovery planning services, and corporate data protection.
This was first published in March 2009