LSI Nytro MegaRAID NMR 8120-4i Application Acceleration Card Review

This year at FMS 2012, we were met one day by LSI representatives who politely handed us a non-nondescript cardboard box and simply said, “Enjoy”.

We had been waiting for this box for some time and new it to be the LSI Nytro MegaRAID NMR 8120-4i Application Acceleration Card, part of the trinity of new LSI application accelerating products, all of which we hope to be reviewing in due time.

LSI’s new Nytro product family includes the Nytro MegaRAID NMR8120-41 Application Accelerator Card that we are reviewing today, the LSI Nytro XD BLP4-400 and LSI Nytro Warp Drives, all application accelerator cards with a specific purpose in mind. And if you are not certain which would be right for your application, LSI even has the Nytro Predictor Software Tool to help you decide which would be most appropriate for your application.

INTRODUCTION

The principle behind the Nytro MegaRAID card is simple. If your current hard drive-based direct attached storage system is creating storage bottlenecks, the LSI Nytro MegaRAID Application Accelerator Card can alleviate them with a boost from intelligent caching to onboard NAND flash storage. A storage bottleneck tends to keep service times and queue depths high, with CPU utilization kept quite low. With this, quality of service drops and you’re not getting the most out of your processing power.  You don’t necessarily need an app to tell you that, but LSI’s Nytro Predictor Software Tool can run in the background and collect system trace information to look for places where faster storage could make a difference, then letting you know which one of it’s PCIe flash card products would be the right choice. It simply uses common blktrace and xperf system traces, analyzes them, and then lets the user know how any storage short comings could be addressed.

If at the end of the day it turns out that your HDD-based direct-attach storage subsystem is holding you back and you have a pattern of some heavily accessed data with lots of more infrequently needed data, the Nytro MegaRAID Application Accelerator Card could be right for you.

For other situations, perhaps you might look at LSI’s PCIe flash card, the Nytro Warp Drive, or the similar Nytro XD for intelligent caching of hot data to 400GB of onboard flash, for SAN and DAS environments. Those two solutions are both PCIe based flash cards, but the XD is for caching, while the Nytro Warp Drive is a straight PCIe flash card for accelerating primary storage. LSI’s flash-based product stack is small in terms of number of products, but comprehensive in terms of scope.

LSI’s new Nytro MegaRAID card is built with a combination of the LSI technologies, but it is at it’s heart a RAID card, one based on the LSI SAS2208 800MHz Power PC-based RAID-on-Chip (RoC). The SAS2208 and 2308 are PCIe Gen 3 chips, raising the max throughput over their Gen 2 predecessors. That is the foundation upon which the Nytro MegaRAID card is based, but uniquely integrates Nytro caching software, built on similar caching algorithms as LSI’s CacheCade 2.0 software and LSI SandForce flash storage processors.

CACHECADE BACKGROUND

LSI’s CacheCade software can be purchased for LSI’s MegaRAID cards and, in a nutshell, it allows for HDD arrays to be cached with SSDs. The first iteration of CacheCade, 1.0, was much the same as the newer CacheCade Pro 2.0, but it had the distinct limitation of only caching reads. With CacheCade Pro 2.0, that limitation finally disappeared, leaving the door open for a customized read and write cache solution. If you take some hard disks, solid state drives, and a LSI MegaRAID 9265-8i with CacheCade for example, the SSDs could be used as a caching volume to accelerate the HDDs. Instead of using software to handle the caching algorithms, CacheCade uses the RoC to keep track of which logical addresses to cache, and which should be left alone and serviced from the slower hard disks.

To effectively create the Nytro MegaRAID card, LSI needed one other piece to complete the puzzle. The SandForce purchase provided LSI with the Flash Storage Processor (FSP) to make their own Nytro flash modules, the two onboard flash modules powered by LSI SandForce technology, rather than relying on and validating that of outside companies. Having an in-house, thoroughly validated controller just makes sense when your goal is to build a product such as the Nytro MegaRAID. Getting the whole package together and validated in a drop-in unit will be far more attractive than rolling your own caching set up for many of those making purchase decisions.

For an enterprise deployment of CacheCade, you’d first have to decide which SSDs to buy separately. The Nytro takes the guesswork out of it, providing buyers with the option of eMLC-based flash modules in 100GB, 200GB, and 800GB versions. This also means that the buck stops with LSI should an issue arise.

The 100GB varient of the Nytro MegaRAID is dubbed NMR8100-4i with an MSRP of $1795, the 200GB is the NMR8110-4i at$2795, and the 800GB is known as the NMR8120-4i with suggested retail pricing of $6995. Each is a half-height, half-length card on a PCIe Gen 3.0 x8 interface. The two onboard cache drives can be set up as RAID 0 or RAID 1 configurations, depending on the need for performance or redundancy. Most hot data is a comparatively small subset of the overall amount of data, so a little cache can go a long way. The 800GB model is suitable for caching an absurdly large amount data when run in RAID 0, perhaps even into the double-digit terabyte range depending on the data. That’s the one we have in house today, so we’ll try it out in various configurations.

Dropping the Nytro MegaRAID in as an upgrade is almost plug and play. All that is required is the installation of the driver and setting up of which volumes to cache. The effect starts immediately, though it takes some time to fully ramp up as we’ll see later.