Myth #5: Tapes are just too slow
Disk can be used to provide fast backup and retrieval for some applications because it provides random file access. Tape must move sequentially through the tape to a specific section. However, not all data needs to be accessed fast or frequently. Some data may go to secondary disk and expire there. Some may move from secondary disk to a tape archive. Some may go directly to tape without having to use expensive disk space. And, when the data is moved to tape, it can be quite fast. The newly announced LTO Ultrium-4 specification calls for native drive data rates up to 120MB per second. That will be able to stream up to 864GB of compressed data per hour. This far outperforms any of today’s SATA disk backup speeds.
Myth #6: Disk is now cheaper than tape
Disk prices have continued to decline. This price erosion became more apparent with the introduction of higher capacity, lower performance SATA disk. Many now claim that disk drives are less expensive than tape systems. They quote the average cost of a gigabyte of SATA disk as proof, but these numbers are averages, and averages tell only a small part of the story and don’t always include all of the costs. In fact, averages can be meaningless when comparing what it will cost to store the same amount of data in your environment on disk versus tape. The cost of disk systems varies widely. Dual controllers are more expensive than a single controller. Advanced features, such as management software, can add to the cost. When comparing the acquisition costs of the two systems, the SATA disk systems cost about 6.5 times more than the automated tape system. When adding in space and energy costs the LTO-4 tape library system cost 11x less than the SATA disk system.
Don’t let averages lull you into thinking the cost of disk is less than the cost of tape. The only accurate way to compare costs is to compare the costs of two systems configured with equivalent capacities. This means that tape continues to cost significantly less than disk.
Moreover, Tape is green. Disk drives continue to spin and need electricity to power and cool the devices whether the device is accessed or not. Tape drives, on the other hand, use little power when not reading or writing tape cartridges. Tape cartridges require no power at all, when residing in an automated library.
Myth #7: Tapes get lost
Everyone that has read a newspaper in the last few months or has listened to the news on TV or radio is aware that several large corporations have admitted that their backup tapes have been “Lost”. These tapes never did make it to the final vault. There should always be a concern that tapes containing sensitive information are “Recovered” by people looking to use that information for illegal gains. Tapes will get lost in shipment. Any package that is shipped can, and occasionally will get, misdirected, stolen, or accidentally destroyed.
There is a simple answer to this problem and it is called “Encryption”. Any confidential data that is shipped offsite, whether it is shipped on a tape or over a network, should be encrypted. Then, when the data is “lost”, the contents cannot be used for malicious gain.
Is it hard to encrypt tapes? Encryption is easy (managing the keys is the difficult part). Backup software has imbedded encryption that can be used to write encrypted backups to tape. There are appliances that encrypt data before it is sent to the tape drive. Moreover, native tape hardware encryption has recently been introduced by IBM on tape drives and is also available on LTO generation 4 tape drives. Tape drive encryption is fast and doesn’t consume server overhead like software encryption. The drives can do encryption at rated speeds and they can compress the data first and then encrypt helping to maximize storage capacities. Tape drive encryption can also help reduce the storage infrastructure by eliminating the need to invest and manage an encryption appliance.
Tape encryption is important. Having an enterprise-wide security plan is critical for every corporation. If you don’t have a security plan in place today, you need to start planning today. Encrypting tapes must be part of that plan.
There is more work being done. Radio Frequency Identification (RFID) is in use by many corporations and the United States Government to track inventory. Similar RFID technology will soon be available for tape cartridges to track cartridges as they move from one location to another. Other technologies are also under development that will allow tapes in transit to be tracked continually.
Myth #8: Tape is not part of best practices
Oh, contraire! Try telling that to the major insurance, Wall Street bank, and retailers of the world that all have strategic investments in tape technology.
Putting all your eggs in to one technology backup basket is dangerous. Having more than one media type for storing critical data is important in the event of a media catastrophe. Therefore, a copy on disk and a copy on tape or optical is essential. Tape is removable and once removed from the system is not susceptible to system errors, viruses, or sabotage. Having more than one… more than two… even three copies of critical data is becoming the standard. Losing access to critical data is more costly to a company than the investment in the storage systems. Best practices dictates that an enterprise should have one copy of critical files at the primary location and then a second copy at a remote location, (or at two different locations) to prevent loss of data if a regional disaster occurs. And as we have previously discussed, tape fits this bill nicely with its portability, reliability, and favorable TCO.
Myth #9: Tape is boring
Tape is boring – try telling that to a tape engineer that is developing the next higher capacity tape drive or automated library robot. In the reel-to-reel days of tape, it was comforting to watch the tape reels spin. Spinning tape reels gave those of us that worked in the data center a sense of confidence. Spinning tapes meant that jobs were executing and productive work was getting done. Those of us that worked in the data center were not the only ones that enjoyed watching tapes spin. Spinning tape drives were the back-drop for many movies to give viewers a sense that technology was at work.
The fun of watching tapes disappeared when tape reels were replaced by cartridges that were small, compact, and the mechanics were hidden from view. Nevertheless, the fun returned with the invention of the automated tape library that was done by IBM. The robot would move very quickly along the walls that housed tape cartridges, retrieve the correct cartridge and mount it into a tape drive. The original libraries were constructed of solid walls that did not allow people to view the robot. Later, the vendors understood that people were fascinated with robots and windows were added that allowed people to view the high-speed activity of the robot.
In one data center, the night operators decided to “dress up” each robot. The next morning, the day shift operators were crammed around the windows of the libraries laughing as robots with brightly colored ties, sunglasses and straw hats went whizzing by.
It has been 55 years since the first commercially available tape drive was marketed to data centers. Tape drives today do not look at all like those first drives. Engineering developments throughout the years have brought us faster, more reliable and higher capacity media and drives and the development shows no sign of abating. Tape’s role in addressing compliance with WORM, data retention with archive, data security with encryption, data protection with safely-removable cartridges and TCO with low acquisition and operation costs is strategic in the storage hierarchy.
Tape, like disk systems, continues to evolve. That evolution ensures tape’s place in the data center today and in the future.
By Mohamed El Mofty
Storage Networking Solutions Expert
IBM Systems and Technology Group