D2D Deduplication Virtual Tape

Tape is not dead!

I am amazed when I hear some vendors aggressively promote that tape is dead. It seems that hyping the demise of tape is in vogue these days and the reality is quite different. Even so,  there is no stopping them from sharing their message with anyone who will listen. If you ask large enterprises, many of them are looking at alternatives to tape, but telling them that tape is completely dead and that they should rip out all tape hardware is ludicrous. Ironically, this is the approach of some deduplication vendors.  Jon Toigo states this succinctly in his blog.

The problem with tape is that it has become the whipping boy in many IT shops.
Courtesy: Drunken Data

The simple reality is that tape has been an important component of data protection for years and is likely to maintain a role far into the future. The reader should remember that in today’s highly regulated environments, companies often face strict requirements about data retention. For example, medical institutions can face some of the most stringent requirements:

HIPAA’s Privacy Rule, in effect since 2003 or 2004 depending on the size of the organization, requires confidentiality of patient records on paper and sets retention periods for some kinds of medical information, regardless of media. These retention requirements can stretch from birth to 21 years of age for pediatric records, or beyond the lifetime of the patient for other medical records.
Courtesy: Directory M

With this in mind, let’s look at the evolution of tape:

First there was tape…
Prior to the advent of low cost disk drives, tape was the primary method of data protection and backup applications were architected to support tape. This was the driver of the media management abilities that are so prevalent in today’s backup applications.

Backup was relatively simple in these days. There were limited regulations and companies had few cost effective options outside of tape.

Then there was low-cost disk…
As low-cost disk emerged, most backup ISV’s recognized the benefits of the new medium and added a disk backup option. It is important to note that most disk backup implementations were developed to augment, not replace tape and were not nearly as mature and reliable as their tape-based counterpart. The immaturity of disk support was not deemed to be a problem since customers were only expected to retain data for short periods of time on disk.

VTL’s emerged around the same time. They were created to leverage the robust support of tape in the backup application while providing the performance and reliability of disk. The technology also allowed customers to retain data on disk more effectively since it leveraged tape media management. In practice customers typically retained more data on VTL than the disk-as-disk option described above.

The inclusion of disk into the backup process added complexity since the administrator had to decide how much disk to purchase, how much data to retain on disk and how to configure the disk subsystem for optimal performance. In all cases, disk was used for retaining data for a relatively short period of time (few days to a few weeks) and tape was still used for long-term retention.

Then there was deduplication…
Deduplication changes the economics of disk-based data protection. It allows for a dramatic reduction in $/GB although and as posted before, it often leads to a reduction in restore performance. It also allows for more cost effective replication since you can often use the technology to power the replication of deduped data. (e.g. sending only net new data over the wire.)

The explosion of deduplication solutions has lead some deduplication vendors to say that tape is no longer necessary and that all data should be backed up to disk directly and then replicated to a remote site for DR purposes. Is this really a valid approach for all companies? In short, the answer is no.

Small businesses traditionally have much less investment in physical tape and their environments are relatively simple.  Thus, they are often looking to reduce the dependence on tape since it adds management complexity. The tapeless message resonates most with these users.

The situation is completely different with enterprises. These companies have strict business and data protection requirements. For example, as quoted above, hospitals are required to retain some data over a patient’s life time. Enterprises are typically already using disk and have substantial investments in tape. If you ask them whether they are willing to instantly rip out tape and replace it with disk, the answer will uniformly be no. Their conservative nature, strict business requirements and massive investment in tape means that they are not looking to radically change their processes. They may have a long-term goal of going tapeless, but their implementation process will be gradual and some applications may never move away tape.

In summary, saying “Tape is dead” is a generalization that only applies to a small subset of the market. In the enterprise, where SEPATON participates, companies are looking at VTL deduplication solutions as a way to enhance data protection, improve their current tape operation and provide a future path to reduce tape usage.  (On a side note, it is ironic that the guy posting this works for a company whose name is “No Tapes” spelled backwards!)  In general, I believe that tape is similar to mainframe computers. People have been forecasting the death of mainframes for the last 17 years (See this article from IBM), but the business keeps going and so it is with tape. And so if you run into a vendor telling you that tape is dead and I suggest that you answer, “Yup, just like mainframes are dead!”

2 replies on “Tape is not dead!”

You are badly misinformed. We have been selling VTLs for many years and position the technology as a way to augment existing tape policies. Do some customers go tapeless with the VTL, sure, but the majority do not. If you are looking to point fingers at the tape is dead crowd then you should post this blather over at dedupe matters. They are the primary proponents of these messages.

Clearly you have been overdosing on the HDS-IBM/Diligent Kool-Aid.

Leave a Reply

Your email address will not be published. Required fields are marked *