The response to our announcement last week of the first members of our new E-Series storage family has been truly amazing. In Part 1 of this series, I told you a bit about our design philosophy, so today I’d like to introduce you to the technology and some of our newest innovations.
The first thing that people notice is our new Active Drawer™ technology. It’s something our engineers started working on over five years ago, as part of our quest to deliver higher and higher density without the sorts of painful compromises that had afflicted our competitors’ earlier efforts. When we announced a chassis in 2002 that packed a whopping 42 disks in 4U, it was a game-changer. As time marched on, however, it became clear that 60 drives in 4U was the next milestone, but we just didn’t like the idea of having to slide a honkin’ big 300 pound chassis three feet out of a rack to change a drive (a process likely to involve at least two people, a stepladder, gigantic metal barn doors, and quite possibly an ambulance). There had to be a better way.
There were a few vendors that tried to improve density by creating disk packs that could plug into a shelf, but all the drives in a pack had to be taken off-line in order to change just one of them, necessitating a huge RAID rebuild once the pack was re-inserted. Rumor has it that at least one of them attempted to speed up the rebuild by scoreboarding changed stripes, but I guess for whatever reason they gave up on that approach. Another problem with this approach is that in order for the canisters to be safely handled by one person, they could only carry a relative handful of drives, which means that a lot of them would be needed to build a 60 drive unit, increasing costs and reducing reliability.
After years of development and experimentation, we settled on a drawer system, with three drawers each with 20 drives, each drawer permanently connected by a redundant pair of custom power and data cables that slide in and out as the drawer moves. We call it Active Drawer because our system is able to sustain I/O to any of the drives in a drawer, even when the drawer has been pulled out to add or change drives. This means that the other drives are not impacted during a maintenance process.
It is a common misconception that the goal of high density is to reduce rack space requirements. That’s nice, of course, but it’s not the reason we create these amazing designs. Rather, the real win from high density is in the reduction of components and complexity required to implement any given amount of storage. Less parts means greater reliability and lower power; less complexity means fewer installation headaches and quite possibly a big win in long term reliability as well. And it’s usually cheaper.
In the spirit of “no-compromise”, we wanted to ensure that the design could accommodate even the most power hungry 15K SAS drives, while at the same time being an economical solution for SATA drives and a worthy home for ultra-high IOPS SSD drives. This was partly an electro-mechanical challenge, necessitating state of the art power, cooling, and vibration-control technologies, but also we needed a major jump in RAID controller technology.
Our latest RAID controller design is the beating heart of the new E-Series products. It’s much faster of course, but amazingly it uses less power and is half the size of our previous generation. Much of the improvement is due to our transition to PCI-Express Gen2, but also we completely re-designed our custom hardware RAID engine, and moved to a new generation of support silicon. We also went to a dual core CPU, but unlike many of our competitors who need gigantic, power-hungry, processors to do their RAID calculations as software subroutines (RAID 6 or other multi-parity schemes in particular are huge power pigs when you do it in code), we took the time to create a custom-designed hardware RAID card with a custom-designed RAID chip that does all the heavy lifting, so our processor is relatively lightly loaded.
Another cool thing about our new controller design is that we put the host I/O on pluggable cards. This week we announced our dual 8 Gbit Fibre Channel I/O card, but others are coming right behind it including dual 10 GbE iSCSI, and a dual SAS card (the latter for DAS applications which are surprisingly common among our customer base). We plan to let moderately tech-savvy customers change the cards themselves if their interface needs change, or we can swap it various other ways.
There’s a lot to love about our new E-Series family. We can pack 1200 TB into a single rack, using field-proven enterprise-grade 2TB SATA drives (1800 TB when the 3 TB enterprise-grade drives come out in a quarter or two), or if SSD is more your thing we can deliver about 1,000,000 truly random IOPS in the same space. For archival applications, or applications that have periods of downtime like D2D, we have added an even deeper level of power savings called AutoMAID® Level 4 that can reduce the power consumption of this 1.2 petabyte rack of storage to about 2 KW compared to alternative vendor solutions which consume as much as 20 KW for the same capacity.
The first three members of the E-Series family are the NEXSAN E18, which holds 18 SAS or SSD drives in only 2U (these are 3.5” form factor drives, mind you, so this is very dense indeed), the NEXSAN E60, which holds 60 drives in only 4U, and the NEXSAN E60X which is the expansion chassis for the E60 (giving you a total of 240 TB in 8U including redundant RAID controllers and power supplies). In the next blog post in this series I’ll tell you more about how our E-Series drives efficiency to a new level.
Sometimes I feel like Steve Jobs – just when some of my competitors have caught up with some of our specs and copied our features, we release something new that leapfrogs ahead and sets the new standard. Take a stroll over to our newly-updated website and have a look – we have videos, white papers, and all sorts of new stuff. We’ve invested heavily into the web infrastructure to make our site much more dynamic and useful, so let us know how we can help you.