How many times have you read that Gartner said 71% of tape restores fail? Google it. You’ll find dozens of references to this Gartner “statistic.” It was cited again recently in an article by Highly Reliable Systems, along with a bunch of other stats about how tape sucks. I saw Dave Russell of Gartner last week and asked him about this statistic. He said he had never heard it, but that he would look into it. It turns out that the only way he could find it was to Google it. He searched Gartner’s entire archive and could find no paper that ever suggested at 71% failure rate for tape restores.
He said, “I am somewhere between annoyed and pretty darn angry about what I believe are continued misquotes re. Gartner and tape failure rates. I’ve been the lead analyst for backup and recovery technologies since 2005, and none of what’s out there have been published during my watch.” The only report that referenced tape and the number 71% was a report David did in March of 2006. Here is what it said:
New, and less-expensive, disk options make the use of disk for faster recovery a more viable option than backup to tape. In a poll of 252 attendees at the 2005 Gartner PlanetStorage conference, 26 percent reported that half or more of their recoveries were currently done from disk. That number jumped to 62 percent when the time frame was extended to 2007. As they look five years into the future to 2010, 71 percent expect that tape will be used mostly for archiving and disaster recovery.
I did a bunch of web searches for “Gartner 71% tape restores fail,” and found that if I search for those words prior to March of 2006, I don’t find much. I do find an article from Jon Toigo in 2005 that says he hears IT people quoting a 10% failure rate from Gartner, but he believes that number is fictitous (which it probably was.) I also find a whitepaper from Exabyte that refers to a 2002 article from Adam Couture of Gartner Group. I just asked David Russell to see if he can find that article. I also found another whitepaper from Tandberg citing similar numbers and the same paper. Maybe that one has some basis in reality. Most interestingly, I did find this page which claims to be the text of a Feb 2003 article from Computer Technology Review that says that “A recent study [it doesn’t cite the study] found that while tape backups are used extensively, restoring data from a tape backup system fails an astounding 70 percent of the time. The reasons for such an alarming rate of failure range significantly–and may vary from bad tapes or tape drives to the inability to find the backup tapes or careless processing by IT staff.” (My experience has been it’s been far more careless processing by IT staff than bad tapes.)
The important thing is that prior to March of 2006, a Google search shows no references to Gartner thinking that 71% of tape restores fail. Then David Russell wrote his report in March of 2006 that said that “71 percent expect that tape will be used mostly for archiving and disaster recovery.” If you change your Google search to the year after his paper came out, you find a bunch of quotes to the 71%, the first of which comes from this DPM Datasheet from Microsoft — promoting DPM. Then all of the sudden, the floodgates are open and everyone is quoting this number — no one (including Microsoft) actually giving their source, other than simply saying “Gartner said it.” Most of them also seem to quote the Yankee Group (saying 42%) and Strategic Research (54%). I wonder if they ever said what these articles say they said.
Another quote I’ve seen is this: “according to Ben Matheson, group product manager for Microsoft’s “Data Protection Manager” Division, 42% of attempted recoveries from tape backups in the past year have failed.” (BTW, please note that this is the same number as the Yankee Group number above, so maybe he was just quoting that number) I saw this in an article updated last week. According to LinkedIn, Ben Matheson hasn’t worked for Microsoft since February of 2006, so that quote can’t be correct either. But once you’ve got a great quote, why let it go? Wait, I may have found our Gartner quote culprit. Let’s see, Ben Matheson leaves Microsoft as its DPM product manager in February of 2006. The new person took over shortly thereafter. The next month a Gartner paper is written, and within two months we have the Microsoft DPM product group citing it incorrectly. Could it have been a new gung-ho product manager misquoting Gartner? Then everyone else starts quoting Gartner by quoting this Microsoft paper. Next thing you know it, it’s real! (This is just conjecture, of course. Don’t sue me, person who took over from Ben Matheson.)
We all know tape backups and restores, fail, right? Who cares if no one at Gartner said it? The first reason is truth. This statistic is cited so often that it has been accepted as truth, and it isn’t.
The second reason is that you can’t debate the truth of a fake report. If it was a real report, we could check the stats behind the stat, and see how many of these “tape restore failures” were caused by human error and had nothing to do with the fact that they were using tape. But since there never was any report, we can’t do such a thing.
Please, people. Don’t quote third parties like that if you can’t cite the source. It’s too easy to misquote.
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Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Evangelist at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.