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February 19, 2008



Chuck, the EDL does a great job but it taught me a moerse lesson. Solutions are about products, partners, people and processes. At first bump, I vastly underestimated the complexity of the solution (and I think so did EMC!)

Chuck Hollis

Hi Ronald -- thanks for the comment. But now you've got me interested -- what was the story for you? Thanks.


My story is more like a novel. Something that was meant to take a few weeks stretched to a year. I'll post a few chapters some day over at my blog, so as not to fill yours with my diatribe. However, we did eventually nail that backup window target and never again will I underestimate the complexities in backup. :-)

Jon Tomlinson

We have implemented several CDL's and found it a challenge as well. We are an Outsourcer, and as such operate a medium sized environment that’s leveraged for all of our customers. Here’s my thing. The CDL works as you said. Drop it in and it works. The backup software worked just as it said in the glossy. But there was no integration. Tape is still a factor of course and now we had to find a way to efficiently move images to tape. It was a challenge. Now the new software release should ease some pain. But SUN's idea of having the VTL manage the movement to tape (unbeknownst to the software) appears to have some merit as well. All in all it was the right choice, but certainly easier for a small shop than a large one.

Chuck Hollis

Hi Jon -- thanks for the comments.

We're about to go down a rat hole here, so hang on.

The underlying problem is that your backup software wants to know where things are at all times, e.g which backup images live on which piece of backup media, whether that is a real tape cartridge, or an emulated one.

Everyhing works well when backup images are sent to disk, and stay there. But many people want to move those images again to tape, ideally using the disk library or VTL to do that.

VTLs provide that transparency. When the backup application asks for a tape image, the VTL says "here it is", regardless of its physical location.

Disk libraries don't work that way -- the disk library independently moves images to tape, and -- unless other steps are taken -- the backup management software doesn't know that the backup image has been moved.

EMC has done several integrations with popular backup packages to run a small media-manager on the disk library itself.

In this scenario, when it's time to move from disk to tape (or back), this can be initiated and controlled from the backup application (if desired), but -- at a minimum -- any move is communicated back to the backup management application so it always has an accurate picture of where things really are.

We've done that for Networker and a few other packages. If you're really interested, you should contact your EMC team to find out what the latest is.

And, of course, nothing is perfect. VTLs have pros and cons as well.

Thanks for writing!


Chuck, I know EMC still uses the Falconstor IP for the front-end tape emulation. EMC purchased some other tape emulation IP a couple of years ago - whatever happened to that?

Chuck Hollis

Hi mgbrit ...

You know, I had forgotten all about that acquisition -- can't even remember the name of the company or the technology.

I'm not close to the product team anymore, so I don't know if they're still using Falconstor as a base, or if they added some of the acquired technology, or something else entirely.

Sorry I couldn't help ...


Chuck, hope your trip to Europe has been fun. I have writen my diatribe over at http://thinkingproblemmanagement.blogspot.com/2008/02/backup-window-saga-things-are-not-as.html

You comments on 22/2 are spot on, but it is not possible to go tapeless as I think the auditors and regulators would have heart attacks. Besides, being the cynic that I am, the more fail safes the better.

BTW: Please award your man in France a medal of honor.

The comments to this entry are closed.

Chuck Hollis

  • Chuck Hollis
    SVP, Oracle Converged Infrastructure Systems

    Chuck now works for Oracle, and is now deeply embroiled in IT infrastructure.

    Previously, he was with VMware for 2 years, and EMC for 18 years before that, most of them great.

    He enjoys speaking to customer and industry audiences about a variety of technology topics, and -- of course -- enjoys blogging.

    Chuck lives in Vero Beach, FL with his wife and four dogs when he's not traveling. In his spare time, Chuck is working on his second career as an aging rock musician.

    Warning: do not ever buy him a drink when there is a piano nearby.

    Note: these are my personal views, and aren't reviewed or approved by my employer.
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