« Raison d’Etre for Information Infrastructure | Main | Where Does Grid Go From Here? »

November 18, 2006



Ever think that some enterprises are standardizing on SVC (to virtualize their estate of HDS, IBM, and EMC kit) and want IP protocols (CIFS & NFS, as well as iSCSI) on the frontend?

Using FC protocol on the NetApp in front of an SVC would be weird, but for the IP stuff it sounds like a natural fit to me.

Chuck Hollis

I understand the need -- want to virtualize the entire estate, want choices on the front end to use IP protocols -- no argument there!

But layering one virtualization device on top of another virtualization device just seems like it would be unbearably painful in terms of performance, management and support.

And it's tough. NetApp has all the IP protocols, but hasn't done nearly as good a job as IBM in terms of qual, support and management tools. EMC would sell you two different devices (Celerra for IP, Invista for FC) but would not try and stack one on top of another -- at least, I hope so.

Thanks for reading the blog, and leaving a comment. In the future, please leave a real email address so I can respond with additional detail and color.

Thanks again ..


Hello there Mr. Hollis.

Take this note from an end-user (customer). We are using SVC (its an acronim for SAN Volume Controller) to our satisfaction. Indeed, it introduces an extra level of management into the server-to-storage path, but in our case.
What we do experience though, is that we only have to cope with the server-to-SVC qualifications, as the backend is handled by IBM. This clears us from the always annoying fact that most host-based multi-pathing software just doesn't like to share the host with other vendor's multipathing software. SDD is free of charge, opposed to other vendors charging per host.

To get back on the virtualization stacking, my gut feeling is that IBM's just filling their NAS gap, untill they can fill it up themselves. Maybe in the SVC itself, or by some other means.

They could just be trying things out, to see reponses and see how it incorperates.

In our shop, we would most certainly not opt for the virtualization stacking.

Chuck Hollis

Glad that SVC is working out in your shop. It introduces a few new wrinkles in the landscape, but there's enough known about the environment now that people can make an intelligent choice.

Since I wrote this post, it's become a bit clearer what the logic might have been. IBM has a need to go into a heterogenous storage shop and sell NAS. One way (maybe not the best way) is to have SVC handle the heterogeous storage attach, and the NetApp filer handle the NAS.

But, as you point out, I see this as stacking virtualization, definitely something that should be approached with extreme trepidation.

Thanks for the comment!


How do you feel about a "bump-in-the-wire" appliance now? Is it OK now that EMC is doing the same thing?

Chuck Hollis

Hi -- actually, it's not the same thing, if you think about it.

First, the Celerra VG8 gateway is fully integrated with the underlying EMC storage platforms: functionality, performance tuning, manageability, etc.

That's not the case for a generic NAS head in front of generic storage.

Second, it appears that the newer Intel processors are now fast enough to do serious metadata processing without getting in the way, in effect doing a form of off-loading.

Sure, it's easy to throw names and labels around ... but in this case, I'm pretty convinced there's something more here.

-- Chuck


NetApp aggressive vSeries vFiler can monitor any disks failure and point the finger and tell what physical disk failed via NetApp Operations Manager and NetApp SANscreen.

NetApp SANScreen

Operations Manager

skynet: http://netappsky.com

The comments to this entry are closed.

Chuck Hollis

  • Chuck Hollis
    Chief Strategist, VMware Storage and Availability Business Unit

    Chuck works for VMware, and is deeply embroiled in all things software-defined storage these days.

    Previously, he was with EMC for 18 years, 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 Holliston, MA with his wife, three kids 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 buy him a drink when there is a piano nearby.
Enter your Email:
Preview | Powered by FeedBlitz

General Housekeeping

  • Frequency of Updates
    I try and write something new 1-2 times per week; less if I'm travelling, more if I'm in the office. Hopefully you'll find the frequency about right!
  • Comments and Feedback
    All courteous comments welcome. TypePad occasionally puts comments into the spam folder, but I'll fish them out. Thanks!