Category: Reliability

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Modern RAID Must Protect Against Multiple Temporally Correlated Errors

Modern data protection needs to adapt to protecting modern media. RAID is no exception. In this article I will explain why modern storage consumers need to be asking for certain kinds of protection and not settling for less.

To summarize, don’t bother with storage that can’t provide at least dual parity protection for any given piece of data (whether that’s an array, HCI or the cloud, it doesn’t matter).

Why? Two big reasons:

  1. Because media these days is both larger and fails differently than in the past. Which means Temporally Correlated Errors are far more likely to happen, so you need protection against those. It’s not doom-mongering. It’s based on data.
  2. In the olden days, arrays had small RAID groups that each held a handful of volumes. If something was damaged in a RAID group, at most you’d just lose that handful of volumes. Modern arrays use pools of space, typically made up of multiple RAID groups. This means that you can potentially damage all volumes in an array merely by losing data integrity in a single RAID group in the pool. I’m sure you aren’t exactly looking forward to experiencing that.

I will take you step by step through this, as is my idiom. It is though rather sad that I have to write this kind of thing in 2020…

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HCI Failure Modes and Maintenance

I got the idea for this blog after speaking with multiple customers that were contemplating switching to certain kinds of grid computing/storage (like HCI) without fully understanding the ramifications of doing so.

You see, they were (rightly so) enamored by concepts such as automation, ease of consumption and scaling. But they forgot to ask some very important questions. See here for the dangers of getting too carried away with something new and taking things for granted.

This isn’t a post claiming HCI and grid-type storage constructs are bad. Like any tool, they can be used in various ways, some of them aggressively ill-advised. The point of this post is to help customers ask for the right configuration so they don’t get stuck with a sub-optimal and risky design.

I tried to make this post as short as possible but as someone once said, “Everything should be made as simple as possible, but not simpler”. Which, ironically, is a simplification of what Einstein actually said 🙂

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When Terrified Vendors Attack: The Dell Edition

It recently came to my attention that Dell is now advertising some kind of benchmark that shows one of their platforms can be faster than Nimble in some very specific test of their own concoction.

While I don’t doubt that’s possible (indeed, we could do it the other way around), it may be worthwhile investigating what’s prompting the attack.

I also wanted to point out the various technically fishy points of the benchmark.

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Will your Infrastructure Survive if you Disappear?

This one is dedicated to an old friend that’s been asking me to write about certain technologies like a very specific filesystem and whether it should be used as the basis for enterprise storage.

He loves using open source stuff for business, mostly to save money, but also for the control it affords and the sheer pleasure of tinkering (and, I suspect, a modicum of masochistic proclivity).

This isn’t a post against open source (if nothing else, that would be utterly hypocritical since most commercial stuff is at least partially based on open source software).

It’s more about risk mitigation and TCO.

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InfoSight: How Nimble Customers Benefit from AI and Big Data Predictive Analytics

In past articles I have covered topics about how Nimble Storage lowers customer risk with technologies internal to the array such as:

Now, it’s time to write a more in-depth article about the immense customer benefits of InfoSight, Nimble’s Predictive Analytics platform.

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