From online backups to tape-drive articles! The latest generation of the LTO technology has some interesting features and since these relate to data backups, I decided to share a couple of thoughts with you!
The LTO (Linear Tape-Open) consortium has recently released the 5th generation of tape storage technology. It can store up to 3 TB of data if we assume a compression ratio of 2:1, it has data transfer speeds of up to 280 MB /s, it has a new partitioning feature and Linear Tape File System specification to provide enhanced file control and data management.
It includes two data partitions on the tape that support a tape file system, allowing files to be written directly to a tape and read by another computer, independent of OS or application. That is, we can say it is cross-platform capable and hence, truely portable!
The consortium’s roadmap for scalability and growth is already defined for the next three generations, and they state that the LTO Technology is a powerful and adaptable open tape format created to address the growing demands of data protection in the midrange to enterprise-class server environments. It is evident and understandable that such technology does not appeal to the SME (Small to Medium enterprises) market. I am not surprised at all, since the recent trend of remote online backups is very feasible to SMEs and home users, mainly because of its cheaper running costs.
We all agree that the LTO-5 is a big improvement …but over what…over its own technology!… I do not think that customers that went away from tape storage will return because of this new release! I reckon that the consortium needs to revise some concepts in order to be able to attract all kind of users.
The transfer speed improvement of 280 MB /s is quite good but not enough! Without compression it can go down to 140 MB /s and rest assured that you will never achieve a consistent compression rate of 2:1 while bear in mind the good transfer speeds of SATA 3.0 and SSD drives. Without optimal compression rates the storage capacity can go down to 1.5 TB. If I had to compare device with device then hard drives are much faster and can store same amounts data (while SSD capacity is increasing, SATA drives of 1 & 2 TB are quite common nowadays).
I would like to expand the argument about data partitions on tapes. It is a cool concept but is it that practical? Archiving to tape is not so much bound to the underlying operating system but more to the application performing the operation. Most large enterprises use a backup application that handles all backup and archiving operations and hence, I remain dependent on such backup application. So, if I had to take that partitioned tape to another system would I be able to read it without using the same application? Therefore, I would be loosing the interoperability functionality. This may bring up the idea of removing the application in between and write/read directly to the tape partition as to achieve 100% interoperability. But, if I want to use the tape as a data archiving partition, is it feasible to copy large amounts of data to a slow speed medium when I can achieve faster speeds with other media? For example, disk drives are faster while support for the NTFS format with Linux systems and vice-versa (Ext3 for Windows) has been around for some time now! Therefore, we are platform independent with disk drives as well!
My point is why I should archive to tape when I can do it faster, cheaper and safely too – nonetheless, archiving to disk needs some taught like: having reliable RAID systems, verify features and a good reporting mechanism. However, the physical tapes remain more portable than a set of hard drives but note that their lifespan depend on the storage location, the tape drive head condition and the backup strategy used. A daily full backup reduces the lifespan of both the tape and the drive. From personal experience, some tapes lasted years while others few months!
