Data backup is an essential part of any data center. All the information in the main storage device is backed up into a secondary storage device on a regular basis to prevent loss of data should the main storage device fail. For this purpose, virtual tape libraries (VTL) are gaining popularity as they can work with existing backup softwares and provide better consolidation and faster data restoration.
VTLs cannot be classified under new technology. They have been there for quite some time, but they were buried in the deep dungeons until recently. Their function is the same as that of a physical tape library. But they are slightly more intelligent and optimized storage device.
The problem with traditional storage devices is that they are terribly slow and they occupy a lot of space. More and more devices have to be added to meet the rising demand. After all this, there is a good chance of failure of the devices. Extreme care should be while storing them; they are susceptible to damage if the environmental conditions are not suitable. In case you are very particular about your data, you can multiplex it across multiple drivers. Data restoration takes time with traditional storage devices. You have to locate the file in the extensive collection of backup files, which will finally get loaded into the tape drives. If the file is found, then it’s your lucky day. If not, all the hours spent on searching are a complete waste.
On the bright side, it’s cheaper than other storage solutions. But of course, with so many tapes to be added to the racks, the savings in the long run is not substantial.
A virtual tape library on the other hand, offers high speed back-ups; reports show almost 10 x speeds of tape drivers. This allows for a reduction in both backup time and retrieval and restoration time. With this, more and more number of servers can be backed up in the same time interval.
To add to the bonus, the recovery time is even faster than the backup time since tapes need not have to located and loaded to search for a file. VTL simply streams the data much like an online movie website. Since there is technically no tape, there is nothing to be located and loaded or lost. Most of these VTLs also come with RAID storage feature.
Although the initial cost of the VTLs is slightly on the higher end, they can be easily recovered in two or three years. Also, the softwares to handle VTLs are much cheaper as the software tier depends only on the number of tapes rather than the size of the tapes. Scaling a VTL service is a breeze.
The one disadvantage is that the paperwork (read service agreements) for VTL is a big bore and all of it has to be taken care of by data center IT staffs.
Changing your entire backup system is not feasible at one go. It is a more pragmatic approach to incorporate a VTL system to your existing tape environment, see if your data center finds it useful and then inculcate it full fledged.
Some companies help make VTL transitions smooth. You can look up Data Domain and Data Span for their services.
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