For example some implementations send back updates back to the backup application when an export is performed. This way i believe that the backup application is aware of the export operation that way. I think the approach is to make the backup application more VTL aware. I’m sorry i dont have any weblinks for this.

But you can take a look at scache.com to see our integrated VTL approach.

Dual copy by the backup application in the case of a standalone VTL means additional burden on the backup server and also on the primary backup network..

Blog ya later!

Joe

Sounds like the Alacritus solution meets the goal that I described in my last paragraph of being an integrated VTL solution that “can communicate more effectively with the backup applications to allow for more flexible control”. I had not pointed out the values of controlling compression more accurately for better utilization. I have not had the opportunity to play with an Alacritus solution, but it sounds like it meets the objectives of delivering a thorough and, most importantly, flexible VTL solution.

Thanks for the comments NickT - keep ‘em coming!

Blog ya later!

Joe

Alacritus (now part of Netapp) does not have this issue and Tape mgmt can be performed either by the VTL or the backup application. Furthermore, data can be restored from tape by the application even if the VTL is lost. Among the several other differentiators of the Alacritus VTL solution thing is that it does Tape optimization.

Since all data compresses differently, the actual amount of data that fits on a given tape will change from backup to backup. Since a VTL must be able to copy a virtual tape to a physical tape at a later time, it is important that the virtual tape be the correct capacity to fit on the physical tape. If it is too large, it will not fit and cannot be copied. Most VTL vendors solve this by making the virtual tape size equal to the native capacity of the physical tape. However, this makes for very inefficient media utilization – at 2:1 compression, half of each physical tape is wasted.

Alacritus has a unique and patented feature that monitors the compressibility of each data stream, and dynamically adjusts the size of the virtual tape to closely match the compressed capacity of the physical tape. Since compression estimation does not actually compress all of the data (it only needs to partially compress a statistically significant sample), there is no noticeable performance impact. The compression estimation function has also been tuned to take into account the different compression capabilities of different tape drives. The result of using compression estimation is significantly better utilization of physical media

So “For your money” Joe you should be using an integrated VTL that gives you *options* , *flexibility* and *significantly* better utilization and cost savings of physical media.

Cheers