21 posts

PSA: Isilon L3 cache does not enable with a 1:1 HDD:SSD ratio

Isilon L3 cache not enablingI recently expanded two 3-node Isilon X210 clusters with one additional X210 node each. The clusters were previously installed with OneFS 7.x, and upgraded to OneFS somewhere late 2018. A local team racked and cabled the new Isilon nodes, after which I added them to the cluster remotely via the GUI. Talk about teamwork!

A brief time later the node actually showed up in the isi status command. As you can see in the picture to the right, something was off: the SSD storage didn’t show up as Isilon L3 cache. A quick check did show that the hardware configuration was consistent with the previous, existing nodes. The SmartPool settings/default policy was also set up correctly, with SSDs employed as L3 cache. Weird…

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NVMe and NVMe-oF 101 with SNIA: queues everywhere!

SNIA dictionaryDr. J. Metz talked with us about NVMe at Storage Field Day 16 in Boston. NVMe is rapidly becoming one of the new hypes in the storage infrastructure market. A few years ago, everything was cloud. Vendors now go out of their way to mention their array contains NVMe storage, or is at the very least ready for it. So should you care? And if so, why?

SNIA’s mission is to lead the storage industry worldwide in developing and promoting vendor-neutral architectures, standards and educational services that facilitate the efficient management, movement, and security of information. They do that in a number of ways: standards development and adoption for one, but also through interoperability testing (a.k.a. plugfest). They aim to help in technology acceleration and promotion: solving current problems with new technologies. So NVMe-oF fits this mission well: it’s a relatively new technology, and it can solve some of the queuing problems we’re seeing in storage nowadays. Let’s dive in!

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Excelero NVMesh: lightning fast software-defined storage using commodity servers & NVMe drives

Excelero NVMesh logoExcelero Storage launched their NVMesh product back in March 2017 at Storage Field Day 12. NVMesh is a software defined storage solution using commodity servers and NVMe devices. Using NVMesh and the Excelero RDDA protocol, we saw some mind blowing performance numbers, both in raw IOps and in latency, while keeping hardware and licensing costs low.

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Hardware has set the pace for latency, time for software to catch up

I can’t recall the last storage system installation that didn’t have some amount of solid state drives in its configuration. And for good reason: we’re rapidly getting used to the performance benefits of SSD technology. Faster applications usually result in real business value. The doctor treating patients can get his paperwork done faster and thus has time for more patients in a day. Or the batch job processing customer mailing lists or CGI renderings completes sooner, giving you a faster time to market.

To reduce the application wait times even further, solid state drives need to be able to achieve even lower latencies. Just reducing the media latency won’t cut it anymore: the software component in the chain needs to catch up. Intel is doing just that with Storage Performance Development Kit (SPDK).

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FAST VP: Let it do its job!

FAST VP in actionNot all data is accessed equally. Some data is more popular than other data that may only be accessed infrequently. With the introduction of FAST VP in the CX4 & VNX series it is possible to create a single storage pool that has multiple different types of drives. The system chops your LUNs into slices and each slice is assigned a temperature based on the activity of that slice. Heavy accessed slices are hot, infrequently accessed slices are cold. FAST VP then moves the hottest slices to the fastest tier. Once that tier is full the remaining hot slices go to the second fastest tier, etc… This does absolute wonders to your TCO: your cold data is now stored on cheap NL-SAS disks instead of expensive SSDs and your end-users won’t know a thing. There’s one scenario which will get you in trouble though and that’s infrequent, heavy use of formerly cold data…

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