I suppose you are referring to the Seagate Barracuda 1.5 and 2TB disks built in China which experience all of DOA, infant and teenage mortality.

The ones built in Taiwan, especially the enterprise-level XT version with 64MB of cache don't have this problem. Interesting customer comments on newegg about this issue. That 2TB drive is twice more expensive at $200, but that's still 12 times cheaper than the $650-700 required for a 500-600GB SAS or SSD drive.

RAID 10? I wouldn't use anything less safe than RAID 6/60 for my precious data. Hot spares are great and work fine for RAID 5/50, I am still trying to find out if Adaptec RAID controllers manage hot spares in RAID 6/60. They are less important since RAID 6 allows 2 simultaneous drive failures, but still, at a cost of only a $200 disk, it saves a lot of technician time.

* Sorry, "Adaptec", not "Adapter"
http://www.adaptec.com/en-US/products/Controllers/Hardware

They actually have only 2-3 such boards, so we're not there yet. You don't need SSD disks for the caching, the cache is on board, but I just checked, it's a ridiculous 4GB for an extra $330 compared to the non-SSD cache model. So it's more like $83/GB.

4GB is what you get on hybrid SATA/SSD disks, so I guess it is not adequate for a RAID controller that can handle 256 disks.

I've read some people are starting to mix SATA and SSD: SATA arrays for backups, documents storage, etc., and SSD arrays for high IOpS data such as database read/write transactions.

Since SAS and SSD disks are basically the same price, $1.2/GB for SAS and $1.4/GB for SSD, with SSD prices dropping continuously, no mechanical parts, pure NAND memory speed, mixing SATA and SSD arrays makes sense, and you can drop global storage prices a lot with the SATA arrays.

Still, the lack of SATA III controllers, the small size of the SSD cache, and the few glitches with SSD drives after many write operations would make me wait until these issues are resolved.

SAS is doomed!

Try Adapter SAS/SATA RAID controllers with SSD caching, SSD disks are about $7/GB, so the cache are probably in that range too, not $2,000/GB.

Wow, where do you come up with $8.6/GB?
Hitachi's 300GB SAS disks are about $350, so that's $1.2/GB raw.

If you are talking usable space, say you have 10 disks per shelf combined in RAID 6, that's 7 usable disks, 2 for data parity, 1 as hot spare. Add another shelf for backup, that's still only $3.3/GB with RAID redundancy, backup and hot spares (probably removing another $19.5/GB from the lines for backup disk, DR backup disk, DR disk, DR backup disk, and the tapes, that really don't scale for big datacenter. $3500/TB tape "software"?

SATA III enterprise-level disks have the same 64MB cache as SAS disks and will probably have about the same IOPS once SATA III RAID controllers come along, plus controllers already use SSD caching for even better performance, so the cost of the same configuration as above is only $0.2/GB, for 14TB of usable space in 1 shelf, compared to 2.1TB with the Hitachi SAS disks.

Now that SSD is starting to mature, I think SAS SANs are doomed. SAS will never reach the same performance and reliability as SSD (no mechanical parts) for the same price. Even now, SSD raw disk cost is $1.4/GB ($700/512GB) compared to SAS $1.2/GB.

It's $11K for 90TB using 2TB disks at $200 each.
More like $40-50K with power, human resources and real estate included.
You need 11 of these to make 1PB, about $120K for the hardware, $0.5M everything included, 12 cents/GB for the hardware only indeed, but 50 cents/GB all included.

@zonky, it's raw storage prices but the cost will not change because of network or backup. If you want these figures, consider that you don't have 11 usable enclosures, but 2 sets of 5 mirrored enclosures or 3 sets of 3-4 main, mirror, and backup enclosures for the same price/TB.
Power for 1PB costs less than $4K/year at 11 cents/WH for the disks only, the servers probably add $2K, and you need only minimal A/C in this range.

Mirror and backup is the way to go, not a waste.
The article talks about the waste that would be if each of your 100TB arrays were using only 20-50TB and the full 100TB wasn't planned to be reached before, say 5 years.

I know the agencies can decrypt anything they want to for standard SSL encryption, and probably will if you're red-flagged somehow, but if I understand this article correctly, they can't make legal use of this information without a formal NSL letter first, right?

In that case, if I am using, say https Gmail, can the ISP technically answer such a NSL letter?
The Google IP address is visible in the TCP/IP headers, but isn't the sender and recipient name and IP hidden behind SSL?
Or are the senders and recipients visible because Gmail is using POP4 or whatever protocol that the ISP can read?

$30/GB/month, now I know you work at Microsoft! ^-^
I think this was about the same outrageous cost of storage in the corporate datacenter farm 2 years ago, although there were also different cheaper options for larger storage needs. And there was also a one-time setup fee before even the monthly bills...

So I made a proposal for our own department for a 8TB storage solution, consolidating several smaller file servers into one (plus another for the backup) with this DAS enclosure: http://www.pc-pitstop.com/sata_enclosures/scsat84xt.asp
Cost was about $6K for the 2 enclosures, 2 RAID SATA controllers and 18 1TB Adaptec drives. The servers were scavenged, the OS and backup software was for free, the set up was also provided by us for free. This was a one-time cost for less than a week of what the IT department would bill us, and zero hassle compared to all the paperwork required to fill in such a request, which basically forces you to overestimate the storage space need, as you don't want to repeat this horrific experience. Maintenance was supposed to be minimal, the disks were configured in RAID 6 to allow for 2 simultaneous drive failures, we had also planned for a couple of spare disks already mounted in spare trays to quickly hot-swap failed ones. Basically maintenance was required only to restore the backups or specific files to an earlier restore point in case of data corruption.

You might get a problem with corporate policies that require the use of the centralized datacenter. I left that department shortly after my proposal, don't think it went anywhere.
I'd make the same proposal today, except that, if the storage need requires it, I'd probably get 16-drive DAS towers or rackmounts with 2TB disks (just 8 disks is a waste for RAID 6), about $6K for 28TB of usable space out of 32TB raw space, plus another 28TB for the backup server set in a separate location.

It's quite bad that the $1M / 100TB cost is not detailed in any way in this article, it makes all attempts of comparison futile and impossible.
Thankfully several commenters provided their input, some even mentioning billing $5M per 100TB to their lawyers customers.

My guess is that this $1M represents partially the costs of the hardware/software configurations in existing datacenters, with most of these possibly purchased 2 years ago.
2 years is a pretty long time in IT, with many technological and financial changes, such as SATA III, 2TB disks and SSD, the latter still being rather immature and expensive.

Given the relatively low cost of the hardware, it does make sense to implement a better aggregation/allocation infrastructure, and disconnect the unused servers, but keep them on hold to add extra storage in a moment's notice, or to scavenge spare hard disks. They won't cost a dime if they are plugged but powered off, it's the online storage and maintenance that costs $1M/100TB (if that much.)

That's not how I read the article, it describes datacenters with 40-60% of unused space, I think the goal if to reduce this to something like 20%.
If you manage 10PB at 50% usage, you can reduce it to 6PB at 20% usage, thus saving $40M (at $1M/100TB.)

Hopefully SSD disks will relieve RAM, once the market becomes mature and cheaper at even higher densities.
$3000 for a 1TB SATA II drive is a little bit excessive... ^-^

The article's focus is more about datacenters reducing their unused space from say 40% to 20% for petabytes of storage.
You're dead if you let unused space down to 5%, let alone 1%. Even home users get red flags when their disks go below 10% of free space.

You can't rely on the OS and extra storage space to fully restore deleted files, the OS can reallocate that space at any time.
It's just pure luck each time if you can, although I agree extra space increases your chances.

You should rely on your backups and maybe custom scripts to trap all file delete requests at low level instead, but I don't even know if that's feasible. That would be totally rad!

60 watts? A 2TB performance SATA III drive (not the "green" low power drives) is about 8W (6 on idle, 9 on load).
So that's 8x24*365 = 70KW, more like $6.
http://www.seagate.com/www/en-us/products/internal-storage/barracuda-xt-kit/#tTabContentSpecifications

Anyway, the cost of the hardware is almost zero compared to the other costs, except is you use SAS or SSD drives.

Adding more servers is wasteful only if you have poor storage management.
If you need more space, you should be able to just add a new server and allocate that extra space to the customers who need it, or not allocate anything at all and bill the customers for the actual space/transfer used or for the extra TBs above their quota. You probably don't even need quotas at all with a smart storage management software.