| Many people consider the use of tape for data | | | | There were attempts to introduce HSM into the |
| storage as a thing of the past. Those people are | | | | market with intermediate storage options such as |
| generally not in any major business field, or are | | | | Optical Disk and the use of tape for longer term |
| running perhaps a small computer based business | | | | archival. However this process came and went |
| without a guaranteed requirement to recover | | | | throughout the 1990's and generally tape was used |
| information in any unforeseen event. However for | | | | as a backup and retrieval medium. |
| those who are serious about data storage, tape has | | | | What is the Difference with Tape and Disk? |
| been in the computer industry for several decades | | | | Aside from the obvious differences physically, the |
| now and is certainly not something that has phased | | | | low-level recording technologies using general |
| out over time. | | | | concepts are no different between data tapes and |
| Why is this you ask? Well the main reason is that | | | | data disks. Both use magnetism to encode data on |
| data tape storage gives a supremely robust means | | | | their respective receptive recording mediums. The |
| of data storage. The tapes store data and code and | | | | main difference relates to their implementation and |
| are generally a lower cost system than hard disk | | | | usages. |
| options. However we are all aware that hard disk | | | | The short answer to "what is the difference" is that |
| data storage options are reducing in cost very | | | | disk is a random access medium and tape is a |
| quickly, that does not however mean that they are | | | | sequential one. Disks are usually pre-formatted with a |
| increasing in the ability to be more solid storage | | | | set number of recordable "sectors" whereas tape is |
| options. Tape is still the preferred choice of | | | | written on-the-fly. |
| professionals for long term archives, often in | | | | What is Better – Data Tape or Data Disk? |
| conjunction with a disk data storage system, if the | | | | Perhaps one of the most important facts to consider |
| reasons are not purely cost based. | | | | with a risk management program related to data |
| In what some consider the dark ages of computer | | | | storage is that recovery of data from a data tape |
| data storage systems, tapes were the predominant | | | | that has had impact or water damage is a more likely |
| medium used for storage. What is not common it | | | | proposition than data recovery from a data disk that |
| seems is that they are still used and are in fact | | | | has had impact or water damage. While storage of a |
| considered fast reliable and more likely to be | | | | data disk may be a more compact option, the ability |
| permanent storage options than data disks are. | | | | to recover important information is more likely the |
| The idea of "near-line" storage was developed, and | | | | reason that you are creating the backup system for |
| still exists in the world of mainframe, AS/400 and | | | | your information and therefore there really is no |
| large scale UNIX computing. Many years ago if a | | | | question. |
| request to recover a file was received this would be | | | | If you ask the data recovery professionals which is |
| in the format of a message displaying on the | | | | the preferred method for data storage they will |
| operators screen requesting that they physically | | | | almost always tell you that data tape is the best |
| locate an open reel tape. The message would also | | | | option available to a business that is serious about |
| advise the tape ID or label reference and would also | | | | data retention and the possibility to recover previous |
| tell them which drive the reel should be loaded to. | | | | data that has been archived. They will in many cases |
| After the instructions were followed this would then | | | | of course suggest that you use both systems, one |
| result in a short delay where the operator would | | | | for the ease of data access with data disks for quick |
| recover the data from the tape. | | | | information recovery but the use of data tapes as |
| Now however the operator has been replaced with a | | | | well to ensure long term retention of important |
| form of robotic tape library, and the open reel tape | | | | business information. |
| by tape cartridge that can be handled mechanically | | | | You save your information because you want the |
| (for example IBM 3590 and TS1120, STK 9840, 9940 | | | | opportunity to get it back if there is a requirement in |
| and T10000, and of course LTO Ultrium and DLT). | | | | the future therefore you should be looking at the |
| The process developed from there to the Hierarchical | | | | best option for information retention more so than |
| Storage Management, often called HSM, and offers a | | | | just ease of use, ease of storage or any |
| more "infinite" storage. The use of the term infinite | | | | misconceptions you have regarding data tape. Ask |
| refers to the amount of space available, tape drives | | | | the experts and see what response they give you |
| and media available. | | | | for your important business backup data. |