Jan 272010

Over at The Backup Blog, Scott Waterhouse offers an alternate perspective on why the announcement by IBM of an in-lab tape technology that fits 35TB per cartridge is largely irrelevant to a doomed market.

I respectfully disagree with Scott’s assessment. I also swear that even though I absolutely loathe the song “Killing me Softly”, naming the blog post after that song had nothing to do with my disagreement on his assessment.

Scott takes two arguments:

  1. It seems a lot like previous announcements by Sun that they were going to release $10M+ servers that were just servers, then later come up with a model that allows the development of servers one twentieth to one fortieth cheaper that do the same job.
  2. That there already is a serious decline in tape, and this will trigger a terminal decline.

You may recall that a while ago I linked to a fairly astute piece by Drew Robb over at Server Watch titled “Tape vs Disk: Tape Refuses to be Evicted“. What was most interesting in Drew’s article was this quote:

How are tape sales? IDC references several studies. Tape overall is down, although the slide is mainly at the lower end. Robert Amatruda, a tape analyst for IDC, said that the market for tape automation products below 100 tape cartridges would suffer most. Another IDC study on Asia-Pacific sales from last year showed automated tape libraries to be up 15 percent for the year, while tape drives fell 19 percent. Cheryl Ganesan-Lim, an IDC analyst, noted that disk storage allows better recovery speeds, thus making it suitable for Tier 1 and Tier 2 storage. Tape, on the other hand, is better for deep archiving of rarely accessed data. She expected tape library sales to rise slightly over the next five years.

So tape is down in lower-end, smaller-scale and more immediate data recovery categories, but it is largely holding its own at the high end. It looks like tape’s death isn’t imminent.

A lot of people are quick to jump on the notion that tape sales are declining. What I take from Drew’s article is the logical fact that at the low end of the market, tape is well and truly dropping off. Pretty much every small business that I’m aware of at an IT level have shifted their backup operations from tape to disk (removable or otherwise) in the last 5 years. I don’t see this trend reversing.

But I’m equally not seeing tape “dying” at the enterprise level as well. I recently wrote an article titled “Direct to Tape is Dead: Long Live Tape“. The title was quite intentional – I do see that at an enterprise level the reasons for backing up to tape directly have been falling for years, and this will be the decade where that is well and truly finished off as a “standard” backup practice. However, that doesn’t meant the death of tape in backup circles.

Scott and I disagree usually when it comes to deduplication. My preference for a start is target based deduplication so that it slots into an existing solution, and he raises alternate arguments that moving to source based deduplication is a good thing. Neither argument is 100% correct, and neither argument is 100% incorrect; they’re just different ways of looking at the same problem.

Scott argues that because IBM has come up with a staggering increase in the capacity of tape, they’re going to struggle to sell sufficient numbers of units in comparison to say, LTO-4 media – and they’re going to be unable to raise the price of their products to match the 40 fold increase in capacity:

But I would be willing to bet my last dollar that there will not be any similar increase in cost or in units shipped to offset this. No tape cartridge is going to cost $2000 (roughly 40x what a current LTO cartridge costs). And they sure aren’t going to sell 40x as may of them.

Looking at a cost perspective, I’m not convinced. When we compare say, even a theoretical cost of $2000 per cartridge for IBM über-dense tape capable of holding 35TB uncompressed, and the actual cost of a Data Domain 32TB dedupe solution, the numbers speak fairly heavily towards buying a bunch of 35TB tapes. Even at that price for the media, there will be orders of magnitude difference between the cost of magnetic tape and the cost of fully specced dedupe solutions. (Particularly when accounting for the need for replication – hence, two such units.)

What I’m going to suggest is that we’re seeing an evolution in the datacentre which is splitting off a high end portion – maybe 5% to 10% of the datacentres of the world. There’s an incorrect assumption, I believe, that everyone can solve all their backup and data storage issues with deduplication. I’d argue that given the relative costs of these technologies at the moment, and the inherent need they currently create for replication of solutions, thus effectively doubling (at times) of prices, and the relatively huge (by comparison) CapEx costs associated with doubling those purchases vs the relatively small ongoing OpEx costs of media, there will be a significant portion of the datacentre that continues to work with tape on a day to day basis and will continue to upgrade those tape technologies to the ones which give higher capacity.

I’d go so far as to diagram it as follows:

Disk and tape usage in backup

Obviously I’m not trying to make the above diagram scientifically accurate. What I’m trying to highlight is that top 5-10% of businesses in the enterprise arena who will more than likely ditch tape altogether in the backup arena. (I will make no predictions on archive.) I fully agree that there’s an evolutionary trend for this ditching of tape entirely in certain datacentres, but only in the biggest.

What I’m increasingly seeing is that there’s a marked difference between what small percentage of high end enterprises do and what the rest of companies that are classified as “enterprises” do when it comes to backup and recovery. This is driven by cost, availability and complexity. Like relativity and quantum physics/mechanics, neither the “dedupe and replicate” nor the “disk and tape” arguments hold true for the entire picture. When looking at the available scenarios from one perspective, it’s clear dedupe and replicate is the way to go. When looking at the available solutions from another perspective, it’s clear disk+tape is the way to go.

My argument simply is that we’re still only at the point where 5-10% of the enterprises out there are suitable for the dedupe only+replicate solutions, and the majority of the rest will still fall into a category of requiring disk and tape. Again, neither argument is wrong, it’s just we’ve seen an evolutionary split in the datacentre between types of enterprises, and those types of enterprises need to be handled differently.

  2 Responses to “Killing me softly? I never liked the song either.”

  1. Well, I can understand loathing Roberta Flack. But the Fugees? C’mon!

    I will give your thoughts a good think, but some initial reactions:

    – I think more people will move to the cloud than we give credit for (my long running survey says about 50% of businesses would move to the cloud). I think in the SMB space there is no good reason why it shouldn’t be closer to 80% or more.

    – I also disagree with the notion that 35 TB cartridges make tape any more competitive from a TCO point of view than disk. You need a lot of tape heads to feed those cartridges, vs. just one disk array. And that disk usually gets 30x (with dedup) so a 35 TB Avamar store could easily hold 1-2 PB of data.

    But you have lots of interesting points Preston. I am not dismissing what you say at all.


    • Hi Scott,

      I’m taking a world-wide approach on cloud. What I’m seeing is there’s significant disparity between certain geographic locations (e.g., US, Japan, certain parts of Europe) and the bandwidth they get vs what the rest of the world gets in relation to internet bandwidth (and cost). So yes, there may be a higher percentage in certain regions, but as an overall percentage I’m willing to stick to 10% at best in that regard.

      On the Avamar front, the capacity offering you mentioned is a good point. Like so much of backup and recovery, there’s not so much one right way as multiple right ways, and a couple of “best options” for any one environment.



Sorry, the comment form is closed at this time.

%d bloggers like this: