Tape storage is a type of sequential access storage medium that uses magnetic tape as the storage medium for digital data. Tape storage devices consist of one or more tape drives that move data to and from the magnetic tape. Tape drives are traditionally used for backup and archival data storage. Some key advantages of tape storage include high capacity, reliability, portability and low cost.
What are the main characteristics of tape storage?
Here are some of the main characteristics of tape storage:
- Sequential access – Data is stored sequentially on tape. To access a particular piece of data, the tape drive must locate the correct position on the tape and then stream all the preceding data. This makes tape good for sequential data access, but not for random access.
- High capacity – Modern tape cartridges can store multiple terabytes of compressed data. Tape has much higher capacity than other removable media like optical discs.
- Longevity – Tape media can have a shelf life of 30 years or more if stored properly. Tape is more durable than hard drives for long-term archival storage.
- Portability – Tape cartridges are small and portable for transportation and offsite storage. This makes tape a good choice for backup, disaster recovery and archiving.
- Low cost – The per-gigabyte cost of tape storage is very low, especially for large capacities. The media and drives are inexpensive compared to primary storage like SSDs.
- Slow data transfer – Tape drives have slower data transfer speeds than hard drives and flash storage due to the mechanical nature of tape. Performance is tens to hundreds of MB/s.
In summary, tape offers very high capacity storage and low cost at the expense of slow sequential access. This makes it ideal for backups, archives and large data sets that do not require fast random access.
What are the different types of tape storage technologies?
There are several major tape storage technologies that have evolved over time:
- Linear Tape-Open (LTO) – The most popular open tape format today, with broad vendor support. LTO-8 is the latest generation with 12TB native capacity per cartridge.
- Oracle StorageTek T10000 and T10000 T2 – Proprietary Oracle tape drives with high capacity and performance, up to 8.5TB native per cartridge.
- IBM 3592 – High performance enterprise tape system from IBM. Offers native cartridge capacities up to 10TB.
- Quantum Scalar i3/i6 – Another proprietary high capacity tape technology, providing up to 15TB native capacity.
- IBM Jaguar – Uses linear magnetic recording for high density storage up to 77TB native per tape cartridge.
There are also older tape technologies like DLT, AIT, Travan, QIC and DAT which are now obsolete or declining in usage. LTO has emerged as the de facto open standard for tape storage solutions today.
Why is tape storage still used in the modern era of big data and cloud storage?
There are several key reasons why tape retention remains strategically important despite the availability of cloud storage and more advanced media:
- Low cost – The per-terabyte cost of tape is unmatched by any other media today. This makes it ideal for high capacity, infrequently accessed data.
- Energy efficiency – Tape cartridges consume no energy when not actively being accessed. They offer more “bits per watt” than any other storage technology.
- Physical security – Tape cartridges can be easily removed, transported and stored offsite for protection against system failures, natural disasters, cyberattacks or other threats.
- Longevity – Migrations to new storage technologies happen infrequently. Tape offers a stable long-term medium for retaining data over decades.
- Standards – Open standards like LTO provide confidence that tape-based archives will remain readable even as technology changes.
- High capacity – New tape drives continue to advance in capacity to keep pace with data growth. LTO-9 offers 18TB native capacity per cartridge.
In summary, tape offers capabilities like low TCO, air gap security, and energy efficiency that other storage mediums cannot match. Tape is likely to remain a key part of the storage hierarchy for the foreseeable future.
What are the typical use cases for tape storage?
Here are some of the most common use cases where tape storage excels:
- Backup – Tape is ideal for backup due to its portability, high capacity and low cost. It allows creating archives that can be stored offsite for disaster recovery.
- Archiving – Regulatory compliance and corporate policies often require long term data retention. Tape archives provide safe storage for decades.
- Big data – Tape scales cost-effectively to enormous capacities for storing big data archives and datasets that only need infrequent access.
- Media industry – The entertainment industry relies on tape for cost effective production, backup and archiving of large media files.
- Scientific data – Research data can be archived on tape, reducing storage costs for massive datasets from particle accelerators, genome sequencing, astronomy, etc.
- Cold storage – Seldom accessed “cold” data can be moved to tape while more frequently used “hot” data resides on disk or flash storage tiers.
Organizations typically deploy tape as one tier in a storage hierarchy ranging from high performance online storage to deep archival storage on tape.
What are some examples of enterprise tape libraries?
Enterprise tape libraries are complete backup and archiving solutions that integrate tape drives, tape cartridges, robots, and software management tools. Here are some leading tape library platforms:
- IBM TS4500 and TS4300 – Midrange and enterprise tape libraries supporting LTO, IBM 3592, Oracle T10000 drives. Scales up to 460 PB compressed capacity.
- Oracle SL8500 – High end library supports T10000 and T20000 drives with over 1 exabyte compressed capacity. Includes the StorageTek Tape Analytics software.
- Qualstar Q80 – Economical LTO-based tape library suitable for small and medium businesses. Provides up to 288 tape slots and 120 TB compressed capacity.
- Dell EMC ML750 – Mid-tier LTO library with a single drive and 80 slot base configuration, scaling up to 480 slots and 11 PB capacity.
- Quantum Scalar i3/i6 – Families of libraries supporting Quantum’s proprietary drives and LTO. Capacities from 50 to 8.4 exabytes.
These represent some of the major tape library platforms available today from leading vendors like IBM, Oracle, Qualstar, Dell EMC and Quantum.
What types of tape media are available?
The main types of physical tape media on the market today include:
- LTO cartridges – The most widely used open standard tape media today. Available in LTO-5 to LTO-9 generations with compressed capacities from 1.5TB to 45TB per cartridge.
- Oracle T10000 T2 – Proprietary Oracle cartridges for T10000 T2 drives with 8.5TB native capacity and up to 1TB/hour throughput.
- IBM 3592 – IBM enterprise tape with JD or JZ models storing up to 10TB native and 60TB compressed per cartridge.
- Quantum LTO – Quantum branded LTO cartridges adhering to the LTO standard. Offered in all LTO generations.
- Quantum Scalar – Cartridges for Quantum’s proprietary Scalar tape drives and libraries with capacities ranging from 4TB to 15TB native.
- Sony AIT/SAIT – Advanced Intelligent Tape media in obsolete AIT and SAIT formats with compressed capacities up to 1TB.
The Linear Tape-Open consortium releases new LTO generations on a roughly 2-2.5 year cadence to keep tape media capacities growing in pace with data expansion.
What are some best practices for managing and maintaining tape storage?
Some best practices for effectively managing tape storage include:
- Use dedicated tape management software to track tape locations and contents.
- Label tapes externally with name, barcode, date and other identifiers.
- Store tapes in environmentally controlled areas to control temperature and humidity.
- Occasionally rewind and retension tapes to maintain proper winding and tension.
- Migrate data to new tapes every 3-5 years before media degradation occurs.
- Conduct regular tape drive cleaning and performance testing.
- Use anti-static procedures when handling tapes to avoid ESD damage.
- Handle tapes carefully and avoid physical impacts that could damage cartridges.
- Store tapes encrypted and enable encrypted data transfer to improve security.
- Keep backup copies of critical tape-based archives for disaster recovery.
Proper tape administration, care and handling is necessary to maximize longevity and reliability when deploying tape storage systems.
What are some downsides and limitations of tape storage?
Tape has some disadvantages that should be considered when designing storage architectures:
- Slow data transfer speeds compared to disk or flash. Typical speeds of 100-300MB/s.
- Latency of tens of seconds to load data from and write to tape.
- Sequential access means long seek times to locate and access data.
- Durability decreases over decades, requiring periodic data migration to new tapes.
- Single point of failure unless redundant tape drives are provisioned.
- Tapes can be physically lost, stolen or damaged if not properly managed.
- Tape drives require periodic cleaning and calibration to ensure read/write performance.
- Not well suited for frequently changing data since rewrites are limited.
- Susceptible to environmental threats like heat, moisture, magnetism, and contamination.
Organizations should understand these limitations before deploying tape-based data storage and archiving.
How reliable and durable is tape for long-term archival storage?
With proper care and management, tape can reliably store data for 30 years or longer. However, tape does have finite durability, requiring data to be periodically remigrated to new cartridges. Some factors impacting long-term tape reliability include:
- Tape media uses barium ferrite particles that can degrade over decades, especially in poor environmental conditions.
- The binder holding magnetic particles deteriorates over time, increasing data error rates.
- Tension and winding issues can develop over years in storage reducing readability.
- Hydrolysis and oxidation slowly break down the polyester substrate material.
- 8-9 nines reliability translates to some bit errors at petabyte scales over 30+ year timespans.
- Media must be stored in proper environmental conditions to achieve maximum shelf life.
Migrating to new LTO tape generations every 3-5 years helps mitigate these effects and refreshes data integrity. When properly administered, tape archives can realistically last 30 years or longer.
How does LTO (Linear Tape-Open) compare to proprietary tape formats?
|Factor||LTO Tape||Proprietary Tape|
|Capacity||100-300TB per tape||Up to 10+ TB per tape|
|Hardware Costs||Very low||High initial costs|
|Media Costs||Low cost per TB||Higher media prices|
|Vendor Lock-in||No lock-in||High risk of lock-in|
|Performance||Slower transfer speeds||Faster speeds possible|
|Complexity||Easy to use and deploy||Often more complex solutions|
|Longevity||Proven over decades||Varies by vendor technology|
In summary, LTO provides open standard, highly scalable tape storage at very low costs, but proprietary formats boast higher performance. LTO has proven durability while proprietary tape longevity varies.
Tape storage continues to serve an important, cost-effective role for backup, archiving and large datasets despite challenges from disk and cloud storage alternatives. While not suited for primary storage workloads requiring low latency and random access, tape’s attributes of high capacity, low TCO, energy efficiency and physical security make it ideal for long term data retention. LTO has emerged as a widely adopted open tape standard that enables tape archives to remain accessible even over decades-long timescales.
Going forward, continued tape capacity growth and tape library automation will help expand tape usage into new big data applications. As long as data remains expensive to migrate across storage tiers, tape will serve as the most economical final resting place for the world’s least accessed information.