Sunday, November 16, 2008

Andy Bechtolsheim: Flash Is Here, But Tape's Not Dead

Andy Bechtolsheim, cofounder and Chief Geek at Sun, spoke about Sun's HPC Storage Roadmap this morning. Andy's presentations go at about one slide every ten seconds, so there was a lot of info, most of which I can't talk publicly about in detail. Generally speaking, he argues that compute is becoming I/O bound - CPU clock speed increases are gaining less and less because it's getting harder and harder to get data to the processors. Disk capacity has grown rapidly, but I/O has remained relatively flat. The answer to this problem is flash memory - performance is not as good as traditional memory, but still substantially faster than disk. The cost is coming down at ~50% a year, and now is at a point where storage systems can be built on this technology. For example, and SSD has 8000 IOPs compared to 180 IOPS in a 2.5" HDD.

Andy went on to note that Sun is building a line of storage based on three different approaches (SSD, PCIe, and DIMMs) that will provide very interesting options for very high performance storage. An early version of a storage system based on flash DIMMs will be coming out in a couple of days at SC08. The system is 1U with roughly half the density and 840X performance over traditional disk. It also caught my eye that the recently announced 7000 system gets 192 3.5" disks into a 42U rack with only 7 Kw power.

This gets more interesting in light of Sun's recent open storage announcement called Amber Road, which is aimed at taking advantage of ZFS to pool this flash based storage with lower cost and lower performance traditional disk into a hybrid system to provide better read performance and lower power utilization for the same cost.

Andy was asked by Jim Pepin from Clemson what the implications are for tape. Andy noted that while flash and disk is getting cheaper, so is tape. Tape also has other advantages, like very low power consumption, and "won't go away for the next ten years at least." When asked about MAID, he noted that ZFS will include features to improve the power consumption of traditional disks, but that generally MAID has issues are slow spin up and read times, as well as the wear and tear of shutting down and starting up drives.

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