Resistron: Touch of the PCM deja vus here. In the very early days of phase change memory PCM it was called RMM for Read Mostly Memory. Mostly because of the limited write/erase life that could be guaranteed at that time. Maybe there is still hope! The problem with this request is if if you ask for junk you get junk and then even worse junk. In the end you finish up with what is virtual memory you just kid the users that they are putting the photgraphs that they will never look at into memory but there is nothing there. Esapecially nice if you can charge for it.
@Ron: I also wonder what's the incentive for flash vendors to make a cheaper product at a time when there is such demand for a relatively high value version of flash. It must be easy to say you will get back to them when you aren't quitre so busy.
Since the members get to use the service free of charge (advertisements not withstanding), how can they complain if Facebook accidentally loses their pictures? Of course, some slimey lawyer will try to make a federal case out of it. I think Facebook got it right.
I think the whole thing depends on distributed storage. If you use distributed storage for network balancing and delivery caching, you end up with 'accidental' data redundancy as well.
So if your 'junk' storage fails in one location, you get a breif network pause while it shows up from somewhere else. Think in terms of spatially separated RAID, but with replicated full volumes as well as stripes.
With pricey high quality storage this gets expensive. With 'junk' storage, this is cheap.
Wobbly; So for you the ultimate is just piles and piles of junk memory distributed all over the place, storing what in effect piles of junk pictures. Somewhere it falls apart. The phrase making silk purses from sow's ears comes to mind. Future generations of memory devices that solve the impending SSD problems will evolve, move down the cost learning curve and quality,performance and reliability will prevail. Surely becoming known as the repository of junk cannot be could PR for any company.
It is like saying I can make an airliner in the shape of a square box (or even box of junk) and use computers to keep it airborne. Might be possible, but is not the best or most efficient way to go.
You missed the point entirely. RAID came into being purely to ameliorate the high cost of enterprise storage by replacing expensive drives with an array of cheap drives, algorithms to distibute data and parity, and silicon acceleration.
Early RAID used 'junk' rotating media to emulate enterprise class storage.
When you upload anything facebook, there is more than one copy. It gets pushed around and indexed.
I believe, also, that they do perform local RAID on the FLASH arrays.
So you have geographical spatial distribution of RAID protected data.
Technology really is a marvelous thing. For more information, look into background on what Amazon has done with the elastic cloud.
The space shuttle was just such an airliner, I read an article that said that without the 3 flight computers it couldn't be flown. Another examplke is the FA18 that is aerodynamically unstable. This allows it to do high speed manouevers because it does them naturally but I digress
For a modest fee you can buy an internet appliance that has an integrated web server and can hold all of your photos and you and your friends can access them any time and you don't have to worry about FBook not caring
I chose it because they have a good reputation and support. Western Digital and Netgear have similar products but only trial SW bundled (last I checked). Mine's been running over 2 years without a hitch and is set up with 2 hard drives and what they call RAID 1 which means each hard drive is a mirror of the other so if one fails you can replace it and not lose anything.
No, I don't think a consumer or average commercial customer wants the "cold flash". Mr. Taylor may not realize that low performance may also indicate poor reliability, heavy redundancy will be a possible result.
chanj0...... large RAM cache is needed to keep a db on hard drive within tolerable performance levels, particularly for write operations, because of the very slow random i/o speeds of hard drives. Because flash has much faster random i/o than hard dive, it is possible to have larger databases with a given amount of RAM.
I do hope this changes the industr. Facebook is an industry of itself. So markets can react to take advantage of this clear need. I think in the near future, storage will be a huge business area. Everyone must be ready for it as we generate these tons of data.
how much space or power on a flash chip is actually dedicated to the block-erase process? if flash were simplified to a be a purely write-once media, would it really change the power or density pictures? I'm not sure the argument even stands if it's only directed at packaging: flash systems need a lot of channels to produce decent write speeds, even in the absence of overwrite (erase).
afaikt, the only thing that would change is that flash controllers could become dumber/smaller/cooler.
I think the leadership team of Facebook is becoming business savvy and forcing on profit. The excitement is over and they realize the there is competition out there. Therefore, they realize that they need to cut cost and still maintain good service. This is very smart.
Write once, read never...maybe? Seems all about power savings. Having to spin up a drive or keep an array up for an unlikely access seems unattractive, however, the read latency for the cold flash would only need to be on par with HDD access times. To the extent that the MTBF of HDDs is a function of simply being powered and spinning, cold flash could increase longevity if it remained unpowered except in the rare ocassion where access was necessary.
A Book For All Reasons Bernard Cole1 Comment Robert Oshana's recent book "Software Engineering for Embedded Systems (Newnes/Elsevier)," written and edited with Mark Kraeling, is a 'book for all reasons.' At almost 1,200 pages, it ...