Inside System Storage -- by Tony Pearson

Tony Pearson Tony Pearson is a Master Inventor and Senior IT Specialist for the IBM System Storage product line at the IBM Executive Briefing Center in Tucson Arizona, and featured contributor to IBM's developerWorks. In 2011, Tony celebrated his 25th year anniversary with IBM Storage on the same day as the IBM's Centennial. He is author of the Inside System Storage series of books. This blog is for the open exchange of ideas relating to storage and storage networking hardware, software and services. You can also follow him on Twitter @az990tony.
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Comments (6)

1 ChuckC commented Permalink

We own multiple Gen2 XIV systems and will likely be purchasing a Gen3 soon, so I was glad to see this feature announcement. However, this seems like a bit of an apples and oranges comparison. It would seem more appropriate (and I'd be interested in your take) to compare: <br /> - VFCache vs. the Fusion-IO cards with the directCache or ioTurbine software options <br /> - EMC FAST Cache vs. XIV SSD Caching

2 TonyPearson commented Permalink

ChuckC, <br /> I am glad to hear you are a delighted XIV customer! Yes, agree that this might seem like an apples-to-oranges comparison. However, if a storage admin is asked to investigate adding SSD to their existing environment to improve application performance, than comparing SSD in the server versus SSD in the storage device is indeed a valid comparison of performance boost per dollar spent. <div>&nbsp;</div> <div>&nbsp;</div> <div>&nbsp;</div> I too would like to see VFCache vs. Fusion-IO with appropriate software features enabled, as well as EMC FAST vs. XIV SSD Caching. XIV Gen3 has been found to be 69 percent lower Total Cost of Ownership (TCO) than EMC VMAX, so a comparison of performance boost per dollar spent over the course of three years would need to take that into account. <div>&nbsp;</div> <div>&nbsp;</div> --Tony

3 ausstorageguy commented Permalink

Come on Tony, this is a bit of a stretch isn't it? <div>&nbsp;</div> XIV is an excellent product of its own standing; did you really need to do this? <div>&nbsp;</div> You say this is to help an admin investigating SSD, but if one were to not know and were to read this post, it would just be confusing and cause distrust; this is just FUD. <div>&nbsp;</div> <div>&nbsp;</div> VFCache vs. Gen3 Cache has no relevance what's so ever as VFCache is about solving latency which no in-array magic can solve - that which is external to the array (cables, switches, Et cetera). <div>&nbsp;</div> It's like comparing corn chips to toast, both go in your gob but serve completely different purposes. <div>&nbsp;</div> I think EMC are being pretty forthright with the purpose of VFCache and not muddying up the waters. <div>&nbsp;</div> To give an alternate would be like comparing EMC Avamar to an XIV and saying "Well, XIV doesn't do dedupe and we've got variable length dedupe...." pretty dumb right, two different purposes? <div>&nbsp;</div> You could have easily written a decent post comparing EMC FASTCache vs. XIV Gen3 Caching. <div>&nbsp;</div> Or even VFCache vs. Fusion IO which IBM Resells: <br /> <div>&nbsp;</div> But really what I think you're doing is trying to ride EMC's release for your own marketing, did you really need to? <div>&nbsp;</div> XIV is an excellent array; adding SSD Cache to the Gen3 takes it further, Moshe would be fuming (which I think is a good thing), can you just stick to that and not ride someone else's wave? <div>&nbsp;</div> Or for that matter, not resort to disinformation, it serves no-one. <div>&nbsp;</div> Aus Storage Guy <br /> (Of no vendor allegiance) <br />

4 TonyPearson commented Permalink

AusStorageGuy, thanks for the comments! You cover a lot of issues, so let's take each point one at a time.<div>&nbsp;</div> <div>&nbsp;</div> (1) Did I need to do this? No, but the XIV team asked me nicely to write about this, pretty please, with sugar on top, so I did.<div>&nbsp;</div> (2) This is FUD. No argument there. For those who can't find the FUD sprinkled throughout my post, it is the list of factual disappointments in the VFCache announcement, including, but not limited to, (a) that it only works on select server models and operating systems, (b) that it only works with FCP protocol, (c) that customers are limited to only one card per server, and (d) that EMC does not recommend anything other than ephemeral data to be placed on the card in split-card DAS mode, to name a few. I agree that sometimes FUD is difficult to find for some readers, but in this post I consolidated the FUD into an easy to read table, in the first column, highlighted in bright yellow. <br /> (3) IBM has sold over 5,200 XIV boxes, and the majority are attached to x86-based servers. I would imagine that many of these servers have PCIe slots. Therefore, for those customers that have both x86 servers and XIV storage, they have two new choices to reduce read IOPS latency. The first option is to install an EMC VFCache card inside the servers that need better performance, and the second option would be to install SSD into each XIV module to benefit all attached servers. Both cost money and provide desired benefits, and as such we can compare these two on that basis.<div>&nbsp;</div> (4) I am not sure what waters you felt I muddied. <div>&nbsp;</div> (5) The comparisons you suggest, between EMC FASTCache vs. XIV Gen3 SSD Caching, or between EMC VFCache and Fusion-IO would also make excellent blog posts.<div>&nbsp;</div> (6) Ride someone else's wave? Ha! We have been planning the XIV Gen3 SSD Caching announcement for months. It was a delightful coincidence that EMC put out a similar announcement the same week.<div>&nbsp;</div> (6) Disinformation? My facts and comparisons were thoroughly researched and reviewed by a team of IBMers. Likewise, if I had anything wrong on the EMC side, I would have heard from them or their lawyers by now. Trust me, I know from past experience. However, if you can point out any disinformation, false or misleading statements that they all missed, I will gladly update the post accordingly.<div>&nbsp;</div> <div>&nbsp;</div> -- Tony <br />

5 Ravo1503 commented Permalink

I find this article embarrassing and IBM unworthy, especially when a current and future loyal XIV account (ausstorageguy) points to the FUD, misleading and misinformation that your article represents. As your answer indicates, you probably never will admit the true essence of this article, feel free not to reply on my post. <div>&nbsp;</div> ausstorageguy's observations are spot on, and you article and answers/feedback gives the Big Blue brand not the credibility it deserves <br />

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