SteveJ-restore-test

STORAGE DRIVES DEMAND FOR INTERNET USE. Since IBM introduced the first disk (5MB, RAMAC) in 1956, demand for storage has grown relentlessly, as demonstrated by yearly total disk sales. Disk Vendors have collapsed to 2+1 as we enter the end-game. Storage drives demand for bandwidth, both for data exchange/transfer and backups. Bandwidth demand will track storage sold, lagged by 1-3 years. The proliferation of smartphones with video has driven the explosion of content on social media, and You-tube's "60 hours of video uploaded every minute" is only set to get higher. By 2020, the last 10-fold scale-up of disk drives will be complete with 3.5" drives maxxing at 20-40TB: 1-10,000 hrs video [or for 'action' HD, ~500 hours with MPEG-4 variable encoding/bitrates.] Flash is also in its last 10-fold scale-up and starting to suffer the same scaling problems that began in 2004/5 for DRAM. There are at least 3 candidate technologies to replace Flash and fuel further grow...

I won't be buying shares in any Fibre Channel-based tech stocks as I think the technology will be dead within 5 years for two reasons: Enterprise Storage Arrays will stop being used for high-intensity random I/O, instead being used for "seek and stream", and PCI Flash or SCM Storage will become the low-latency "Tier 0" Storage of choice because of speed (latency), cost and simplicity. Update 1-Feb-2012: Another article by Fusion-io, Getting the most out of flash storage   provides extra links: Flash storage moves closer to CPUs : STEC is moving into PCI Flash cards. EMC: Flash could spell doom for Fibre Channel but don't talk about PCI Flash challenges. Flash storage in post-PC devices advances , general background on Flash memory. Elsewhere I've written Jim Gray's observation, "Disk is the new Tape" should be "Disk is the new CD". That is, Enterprise Storage is best suited for "Seek and Stream", not random I/O. Enterp...

Researching the history of Disk Storage and RAID since Patterson et al's 1988 paper has given me some surprises. Strictly personal viewpoint, YMMV. Aerodynamic drag of (disk) platters is ∝ ω³ r⁵  (RPM^3 * radius^5) If you double the RPM of a drive, spindle drive power consumption is cubed. All that power is put into moving the air, which in a closed system, heats it. Ergo, 15K drives run hot! If you halve the size of a platter, spindle drive power consumption is reduced by the fifth-power. This is why 2½ inch drives use under 5W (and can be powered by USB bus). There's a 2003 paper by Gurumurthi on using this effect to dynamically vary drive RPM and save power. Same author in 2008 suggests disks benefit from 2 or 4 sets of heads/actuators. Either to increase streaming rate or seek time, or reduce RPM and maintain seek times. The Dynamic RPM paper to be the genesis of the current lines of "Green" drives. Western Digital quote RPM as "intellidrive", but class ...

The 7 Millennium Prize Problems don't resonate for me... These are the areas that do engage me: Datacentre Hardware organisation , power, cooling and interconnect fabric Multi-level memory and impact on Operating Systems. Flash as RAM, disk cache or SSD? Flexible Hardware and supporting Systems and Software Internetworking protocols . IPv4 isn't secure, IPv6 is overblown. The piece for the second item, "Multi-level memory" is old and not specifically written for this set of questions. Expect it to be updated at some time.

The other night I was talking to my non-Geek friend about computers and he formulated what I thought was A Good Question : When will they stop changing?? This was in reaction to me talking about my experience in suggesting a Network Appliance, a high-end Enterprise Storage device, as shared storage for a website used by a small research group. It comes with a 5 year warranty, which leads to the obvious question: will it be useful, relevant or 'what we usually do' in 5 years? I think most of the elements in current systems are here to stay, at least for the evolution of Silicon/Magnetic recording. We are staring at 'the final countdown', i.e. hitting physical limits of these technologies, not necessarily their design limits. Engineers can be very clever. The server market has already fractioned into "budget", "value" and "premium" species. The desktop/laptop market continues to redefine itself - and more 'other' devices arise. The 10...