Five Good Reasons to keep Using
Hail, Hail, tape is dead! The
wicked tape is dead! Just as Dorothy was dreaming, so are you if you think tape
no longer has its place within the data center. Predictions that tape would die
a slow death and give way to cheap disk and robust storage array features are
still far from reality. Personally, the perceived move to disk was just way too
sexy to resist as everyone liked the look and feel of disk. But tape still
lingers and there are good reasons for keeping tape around as part of your
overall data protection strategy. Consider the following:
- Data Growth.
Just as change is the only thing constant in this world, explosive data
growth will continue. IDC recently announced in a white paper, entitled "The
Diverse and Exploding Digital Universe: An Updated Forecast of Worldwide
Information Growth Through 2011," that the digital universe is bigger and
growing more rapidly than originally estimated. The research stated that at
the current annual growth rate of 60 percent, the digital universe is
projected to grow to 1.8 zettabytes by 2011. (That's right, zettabytes.)
The question becomes how much data do we keep
and how much do we need readily available? Marcellus Tabor, Manager of Data
Protection at Yahoo, worries in a data backup article about where all his
data will end up. He says, "We need LTO-6 right now, in a big way." Notice
he didn't say he needed disk drive technology, he said TAPE!
- Cost Savings.
Simply put, tape is less expensive than disk for long-term storage. In a
recent Reuters article, "Clipper Group Reports Substantial Cost Advantages
of Using Tape in Tiered Storage," the company reported that over a five-year
period the total cost of ownership of disk-to-disk-to-tape vs.
disk-to-disk-to-disk resulted in a 23 percent savings when tape was deployed
as the end solution for archival. In times when IT dollars are hard to come
by, this kind of savings is too appealing to resist.
No one, however, is negating the importance of
disk in a backup solution, but there is a balance that points in the
direction of using tape to provide additional cost savings. Of particular
interest, the Clipper Group study pointed to the fact that a disk-only
solution is not a replacement for tape when cost is involved. According to
Dave Reine, Director of Enterprise Systems for The Clipper Group, disk
should be used to complement tape. He concluded by saying, "Our findings
show that there are substantial potential savings when using tape in tiered
approaches, and even when you factor in deduplication, tape-based strategies
still provide an estimated 5:1 cost advantage over deduped disk in
Archival. It is true that companies are changing the way they
perform backups. More and more are implementing disk-to-disk. But as
economies continue to change and government regulations force companies to
keep more and more data available long-term, backup of data is going to
continue to grow out of control. This long-term storage requirement will, as
mentioned in the Clipper Group study, solidify tape's roll in data
protection. Will tape be the backup medium of choice? Probably not for
short-term backups. But for long-term archival, where real-time access is
not needed, tape may become the archival medium of choice.
- Green Storage.
The Clipper Group study also reported that energy costs for disk were
up to 290 times that of tape. Let's face it, once data is on tape, that tape
consumes zero power and generates zero heat. I don't know how much more
economical you can get. Granted, you may need to load the tape in the
future, but for long-term archival data that is infrequently or never
accessed, that it is unlikely.
The use of tape as a primary target for backup has
changed over the years. The onslaught of low-cost, disk-to-disk based backup
solutions coupled with the many problems associated with using tape as a primary
target has rightfully enticed many data centers not to use tape in that
capacity. But that does not mean there is no requirement to use tape within the
data center, as the aforementioned five reasons point out. Further, there is
still innovation in tape occurring at vendors like Overland Storage, which is
continuing to move the ball forward in both disk and tape technologies.
- Virus and Data
Corruption. A danger no one likes to talk about is the risks
associated with keeping data accessible and available on disk, which makes
it susceptible to viruses and data corruption. We are all aware that a worm
or virus can quickly propagate between systems and infect every disk within
an organization, if unprotected. Disk-to-disk backups and recoveries
sometimes only aid in the spreading of a virus. Tape archives, on the other
hand, can provide a different form of protection against viruses since they
have little chance of spreading them. Even if a virus does make its way onto
tape, it is impossible for that virus to corrupt other data sets on that
tape or spread within the tape library.