HOLLYWOOD - IBM spoke on the use of LTO-6 magnetic tape for digital archiving at the 2013 SMPTE Technical Conference, here. LTO-6 with a raw capacity of about 3.1 TB is double that of LTO-5 tape. Data rates for LTO-6 increased by over 40% from the LTO-5 tape format.
LTO-6 also supports the LTFS tape file format allowing data to be accessed from tape like it was any other connected storage device (like a hard disk drive or a USB storage device). IBM has released single drive LTFS implementations as open source although it charges for multi-drive library systems. The IBM presentation showed how a LTO LTFS file system can be used on a LAN for a file based production workflow as shown in Figure 1.
The current LTO consortium roadmap projects raw storage capacities of about 16 TB with generation 8. At a recent Tape Summit IBM said that it was developing technology to enable LTO tape capacities of at least 125 TB (the company demonstrated a 35 TB tape in 2010. However, these monster tapes will not appear for several years (likely beyond a hypothetical LTO 10). With doubling of tape capacities roughly every other year a 125 TB tape probably wouldn't appear on the market for at least 10 years...but it is good to know.
The LTO-6 tapes use a shingled magnetic recording technology with overlapping tracks of data to help with the higher storage capacity. LTO-6 does not use barium ferrite magnetic media as does the IBM TS1140 tape that was announced in 2011. Barium ferrite will likely be used in future generations of LTO tape to help boost the storage capacity.
With increasing digital storage capacity for rich media content with higher frame rates, multiple camera capture and higher resolution, professional media content will be increasing enormously over the same period of time. It is likely that petabytes of content generated in a single video project will become quite common in 10 years. Thus a larger archive storage volume will be important to protect and preserve this digital content. For more on these topics you may be interested in attending the 2013 Storage Visions Conference next January in Las Vegas, www.storagevisions.com.
Although hard disk drives can offer lower latency to access stored content, the current capacity growth rate of LTO tape appears to be about 40% annually (according to the IBM talk at the SMPTE conference) compared to the current HDD areal density growth rate of about 20% annually. Although HDDs with higher capacity growth rates are likely with the introduction of heat assisted magnetic recording in a few years time it appears that tape capacity growth will be faster than HDDs at least for the short term.
The current difference in magnetic tape and hard disk drive storage growth rates will help maintain the cost advantage of archiving on tape vs. hard disk drive systems (see Figure 2). With a started archival life of 30 years (under proper temperature and humidity conditions) magnetic tape looks like it will serve as an important storage element in archival storage for many years to come.
Thomas Coughlin is the principal of Coughlin Associates and can be reached at