Good ol' tape will survive cloud era, too!

BANGALORE, INDIA: They said disk drives (HDDs) will kill tapes. Then, they reckoned solid state disks (SSDs) will definitely 'eliminate' them. And now, they feel tapes will not sustain the cloud era. Still, the good ol' tape refuses to bow.

While some would like to term cloud - also considered to be synonymous to disk drives - as the beginning of the end of tape era, there are others who would argue that the relevance of tape has only increased thanks to cloud, which, according to some others, is not a rival, but a complementary technology to tape.

Shuja Mirza, head, Pre-Sales, North India, EMC, says, "This is the beginning of the end of tape era. We see tape acceptability declining for commercial organizations. People want information instantaneously and that is possible only when it is on disk in the back-end. If you do that with tape devices in the back-up, the response will be slow. If restoration takes 30-35 minutes, that information is as good as being not available. Moreover, backing up that information onto a tape device is virtually impossible."

Another oft-stated argument against tape is that it has many moving parts, therefore provisioning it becomes difficult.

"You can club tapes with software, which can allow you to provision protection for your online data, however, back-end tape infrastructure still becomes very bulky and stiff to respond to business SLAs. One can do block level de-duplication, compression, and stuff on tape, but if data is spread on multiple tapes, for a single file recovery, one has to pull out four or five tape libraries, which is not agile. Almost 80-90 per cent of the total time taken for recovery is wasted in identifying the right tape, aggregating it, mounting it on tape library and aligning it to the right position before starting the retrieval process. Moreover, there are chances of data loss on tape. Therefore tape is on the decline as far as its acceptability is concerned," argues Shuja.

Disk proponents argue that when it comes to performance, disks stand out. However, Rohit Vig, director, Storage Sales, Oracle India, points out that tapes can perform much better than disks today.

"Many people are discovering that the 20-year-old adage that 'disk always performs faster than tape' does not ring quite as true in today's cloud-based storage architectures, where the performance of enterprise-class tape robotics and tape formats with file-system-like accessibility may surpass the performance of MAID (massive arrays of idle disks) subsystems, at an appreciably lower price," Rohit adds.

Tape shipment has been on a decline over the past couple of decades. However, it is also true that while it has reduced, its share is still many times more than that of disks. Guna Sekaran R, country manager, India & Sri Lanka, Quantum, notes that despite the growing popularity of cloud storage, tape back-up is still a vital part of an effective back-up strategy.

"Cloud still requires tape as a complementary technology. Until now, data centre managers wanting to protect data in the cloud had two basic options. Either they had to choose storage array-based replication to and from the cloud that provided fast back-up and disaster recovery, but made it extremely expensive to implement, or they had to choose cloud-only solutions, which were less costly to implement, but demanded a rip-and-replace approach and made the process of restores very slow," adds Guna Sekharan.

One argument against tapes have been that data retrieval from them is slow. However, there are some who decline to buy that argument. Barun Lala, director, Storage, HP Indianotes that downtime may still be tolerated, but not data loss.

 

"Cloud and tape complement each other very well. Cloud helps customer consolidate data. Once data is in one place, back-up on a cost effective medium like tape becomes easy. Back-up is the first step in implementing data recovery (DR). After all, limited downtime may still be tolerated, data loss cannot be. Cloud service providers run robust back-up processes, in which tape, being cost effective, is an integral part. Cloud providers have strict SLA agreements with their customers on data availability. With the increasing adoption of cloud, I see more data getting backed up on tape," adds Barun.

Guna Sekharan echoes on similar lines: "What is not well known is that many cloud providers actually migrate their customers' data to tape as a part of their standard offering. Tape is a much lower cost medium to store data on - not only the cost of the storage acquisition, but also when it comes to power and cooling. Disk-only solutions consume much greater amounts of power and cooling. Oftentimes, when a file is needed, policies ensure that the data is migrated back to faster disk.

Shuja from EMC agrees that from a cost perspective, procuring similar capacity tapes will be 30 per cent less than its disk counterpart. However, return on investment is much faster in a disk scenario. According to EMC, which has completely moved away from tapes internally, believes that cloud providers prefer disks than tapes.

"Cloud service providers are not interested in building tape infrastructure, for the reason that you cannot provision a tape as flexibly as a disk appliance. Cloud providers ask us to back up in a couple of hours and restrore in a few minutes, which is virtually impossible with tape," Shuja notes.

On the other hand, Rohit believes that the current trend to consolidate unstructured data into large-scale repositories in the cloud signals another category of storage, which is 'tape in the cloud'.

"Tape is further bolstering the economic model for the cloud as a preferred repository for archiving. Tape's existing cost advantages might become even more compelling as future cloud technology developments occur. Tape in the cloud offers a significantly lower total cost of ownership, better reliability, longer life, and as good or even faster streaming performance than today's disk alternatives. A single storage administrator can manage up to 1 PB in an automated tape library versus 100 TB of disk. Tape may enable cloud storage providers to lower their internal costs and prices far below any comparable disk solutions for cloud archive services, without any discernible performance differences," Rohit adds.

There are two facts to consider here. While data is growing exponentially, tape capacities & technology is improving, too. Customers, especially large enterprises, are adopting disk based back-up and continue to archive data on tape for long term. I see increasing demand for higher-end tape-automation and slower growth for single tape devices," adds Barun.

Shuja, too, agrees that there is still a huge tape following and that tape is still preferred from a compliance perspective.

"Improvement on tape is being asked for by users by conventional organisation who do not want to let go of tapes. Throwing more infrastructure at an infrastructure problem is not the solution. Data is growing day by day and you need a better solution to back it up," Shuja notes.

The main areas where we will still come across tapes will be back-up and recovery, to an extent, for compliance needs and long-term archival storage. One implementation growing in popularity is to D2D where the second D is remote either in a private or public cloud, while the T is used for long-term, private archive. Technologies such as Linear Tape File System (LTFS) will give tapes a longer shelf life.

 

"Tape capacity, performance, reliability, and manageability are continuing to improve. LTO-6, for instance, has a compressed capacity of 6 TB per cartridge. At $100 per cartridge, that comes to just 1.6 cents per gigabyte. A new feature (also for LTO-5) is called LTFS or Linear Tape File System. LTFS allows tape to be used like traditional disks in a drag and drop format. This makes LTO media appear like a disk and is interchangeable between systems without the need to run special software. Essentially, LTFS makes LTO-5 and LTO-6 operate like terabytes of USB sticks," adds Guna Sekharan.

Even after being on the 'death bed' for several years now, tape not only refuses to die, but also keeps redefining itself every time a new storage technology came in, in its bid to survive. Going forward, too, it will.