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Petabyte Storage Array
knight13 writes "Engadet is reporting that EMC is rolling out a petabyte RAID array. From the article, "And if you're ready for that level of storage, there's now someplace to get it: EMC has launched its first petabyte array, a version of the company's flagship Symmetrix DMX-3 system that includes nine room-filling cabinets of drives." The price? A mere $4 million."
JPEGS would that be?
If you mod me down, I *will* introduce you to my sister!
This is pretty interesting in that it's yet another item that we all wish we had just for overkill purposes.
However, I doubt they'll sell many of these. The only places I can think of that would benefit from this are supercomputing institutes, but they often build their own redudant RAID systems and/or NAS systems.
It's nice and all, but seriously people, who's the audience?
Interesting calculation: If you live 80 years, that's 435.5 KB per second -- enough for a TV-quality video of your entire life.
Be relentless!
I was just thinking about how 4 years ago you could build a terabyte array for about $5-10,000 down from many millions 8 years ago. Today, you can get a terabyte for less than $500. In a few years, a petabyte is only going to cost $5,000. If you just buying space for future growth, it seems like a total waste of money.
http://www.archive.org/web/petabox.php
By those who truly care about the human tradition, and spreading the music of the Grateful Dead and other freely available media.
Is this another slashvertisement?
Let's assume for a moment that the average lifetime of one hard disk in this petabyte array is 6.5 years. Since there are 2,400 hard drives, that means that once this thing has been running for a while, you will be replacing, on average, one broken hard drive per day, for the entire lifetime of the array. That's about $350 per day in replacement parts alone!
1 Petabyte is enough pr0n?
:)
For who?
You're new here, aren't you?
Pretty Pictures!
I pity you.
It's amazing how quickly storage increases and prices go down. On the other hand, it's interesting to keep in mind that as amazing as an iPod nano would be in 1985, the invention of paper was the single biggest leap in storage density we've ever seen.
The thing is built around 2,400 500GB hard drives.
I wonder when (if) the average consumer can get 1PB harddrives?
I don't know if Moores law applies historically to harddrives, but if doubling of capacity occured every 18 months and figuring 500GB is the limit size now and the doubling continues into the future:
500GB - Now
1TB - 18 months
2 - 36
4 - 54
8 - 72
16 - 90
32 - 108
64 - 126
128 - 144
256 - 162
512 - 180
1024TB = 1PB - 198months which is 16.5 years.
A petabyte ought to be enough for anybody. And I mean it this time.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
The faster a disk spins, the more disk surface is exposed to the magnetic field used to write to the drive, so the less storage you have. Disk rigidity is important for two reasons - it limits how close the read head can get and it limits how precisely you can know how much disk surface has been visible. The faster you can either read magnetic fields or generate them, the less disk you need to write to, thus increasing storage. The distance of the read head determines the surface area exposed to the magnetic field on writing, so determines how far apart your data must be to not overlap.
A trivial question might be: Using a standard, existing hard disk (but modifying the controller as necessary) increase the capacity of a hard drive? The answer is "probably".
One way to do it would be to add enough RAM such that a fairly substantial portion of the disk can be held in ramdisk on the controller. Because you are then not reading and writing to the disk directly, but going through ramdisk, the speed of the drive becomes much less important. If you slow the drive down substantially, whilst writing to it at the same speed, the data won't be smeared over the disk as much, so you should be able to increase the density.
In practice, as disk manufacturers don't design their disks with that kind of mod in mind, you are very likely to run into significant problems with defects on the surface that simply aren't visible at 7200 or 15000 RPM. Other problems, such as stability (drives depend a lot on gyroscopic effects and aren't built to go slow), may also limit how much you can cheat on the density.
Another option would be to seriously cool the read/write head, so that you could flip the magnetic state faster. Again, you're limited. Mechanical devices don't like being freeze-dried - even when they ARE dry. However, you may be able to get some improvement that way.
If you're just looking for ANY increase in capacity, then that's trivial and requires no engineering (but some programming). Modern computers are very fast, compared to modern hard drives. If you have one physical sector per physical track, then break down the structure entirely in memory, you eliminate the need for inter-sector gaps, physical sector headers, etc. You might be able to squeeze out another 10%-15% by this method, which isn't a whole lot but isn't bad for the effort it would take.
There are very likely other mods that hard disk manufacturers could use, but which would be totally beyond anyone doing homebrew stuff. The platters probably aren't using the absolute ideal materials - let's face it, they're in business to make money and there are far more home buyers wanting cheap drives than there are perfectionists wanting perfect drives. I suspect there are other areas they could improve on, using existing technology, but won't because it's not economic.
That's probably why you see bursts of improvement. When there's a massive enough need for the extra storage, it can be achieved. When there isn't, it's not worth the extra investment.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
With a beast like this that fills up a whole room, anything else becomes a peripheral....
That's generally what you pay a fortune for when you buy these big beasts.
It all boils down to what is most important for you - the money or the hassle of managing less integrated systems. The big filers are by no means the right choice for everybody, but they are nice to work with if you can justify the cost.
Features in high end storage systems like this typically include things like redundant-everything (multiple controllers with automatic failover, multiple sets of write cache, RAID, multiple power supplies), up to and including systems where you can pull out entire packs of drives while the system is running without noticing more than a reduced IO rate.
Many of them also have extensive built in health checks, and some will "call home" and the first you might know about a potential problem may be the engineer showing up at your office to fix it before it does become a problem (of course, you pay accordingly....)
Other features usually involve snapshot support (get a second virtual "drive" that is "frozen" at a point in time - makes doing backups a breeze because you can quiet database updates etc., make a snapshot, and then go on with your business and not have to deal with complex hot backup solutions), and often remote synchronisation (get a second box at a second location, put up a fibre link between them, and let the boxes handle the rest)
Of course you can do most/all of this with cheaper hardware too, but then you have to build it yourself. If you're, for instance a bank, and are dealing with huge sums of money, it's often far easier to buy stuff like this and pay for the maintenance contracts and just not have to deal with it any more.
For mere mortals they are usually just outrageously overprised compared to the features we actually need.
Though I must say I have always had a weakness for hardware that comes with cases big enough to live in and requires forklifts to move... :)
The Internet Archive Project http://www.archive.org/ is running on the PetaBox http://petabox.com/ rack system, which was commercialized by Capricorn Tech http://www.capricorn-tech.com/ more than a year ago.
a beast.html from nexsan http://nexsan.com/ which manages to pack 42 500 GB SATA drives into a single 4U rackmount box. With multiple RAID5 volumes and shared hot spare drives, this results in about 17-18 TB of usable file system space.
This system uses absolutely no board/controller lever redundancy, instead they use a separate file system on every disk, then mirror pairs of 1U units, and finally mirror the entire (mirrored) rack to a geographically distant location.
I am currently testing a much denser solution, the SATABeast http://nexsan.com/products/products/satabeast/sat
According to the nexsan engineer I spoke with today, they do so much burn-in testing of the Hitachi Deskstar drives they ship, that over the 15-18 month period they've used these drives, the total error rate has been just 0.4%.
Even if these numbers are somewhat skewed due to many systems (i.e. drives) being relatively recently installed, it is still very impressive.
For our setup we plan to use multiple full boxes, each connected to a separate NFS server. Each server has multiple FC host adapters, so if a server crashes, the corresponding box can be connected to one of the other servers.
We will also use rsync to mirror all data across the country to a secondary site.
Terje
"almost all programming can be viewed as an exercise in caching"