Posted on 03/08/2016 8:34:18 AM PST by dennisw
Heat doesn't kill hard drives. Here's what does"Free-cooled" datacenters use ambient outside air instead of air conditioning. That lets us see how environment affects system components. Biggest surprise: temperature is not the disk drive killing monster we thought. Here's what is.
At last months Usenix FAST 16 conference, in the Best Paper award winner Environmental Conditions and Disk Reliability in Free-cooled Datacenters, researchers Ioannis Manousakis and Thu D. Nguyen, of Rutgers, Sriram Sankar of GoDaddy, and Gregg McKnight and Ricardo Bianchini of Microsoft, studied how the higher and more variable temperatures and humidity of free-cooling affect hardware components. They reached three key conclusions:
Relative humidity, not higher or more variable temperatures, has a dominant impact on disk failures. High relative humidity causes disk failures largely due to controller/adapter malfunction. Despite the higher failure rates, software to mask failures and enable free-cooling is a huge money-saver.
Background
Datacenters are energy hogs. A web-scale datacenter can use more than 30 megawatts and collectively they are estimated to use 2 percent of US electricity production.
Moreover, the chillers for water cooling and the backup power required to keep them running in a blackout are costly too. As the use of cloud services has grown, the cost of hyperscale datacenters has led to more experimentation such as free-cooling and higher operating temperatures.
But to fully optimize these techniques, operators also need to understand their impact on the equipment. If lower energy costs are offset by higher hardware costs and downtime, it isn't a win. The study
The researchers looked at 9 Microsoft datacenters around the world for periods ranging from 1.5 to 4 years, covering over 1 million drives. They gathered environmental data including temperature and relative humidity and the variation of each.
Being good scientists, they took the data and built a model to analyze the results. They quantified the trade-offs between energy, environment, reliability, and cost. Finally, they have some suggestions for datacenter design.
Key findings:
Disks account for an average of 89 percent of component failures. DIMMs are 2nd at 10 percent. [Disks are the most common component in datacenters.] Relative humidity is the major reliability factor - more so than temperature - even when the data center is operating within industry standards. Disk controller/connectivity failures are greatest during high relative humidity. Server designs that place disks at the back of the server are more reliable in high humidity. Despite the higher failure rates, software mitigation allows cloud providers to save a lot of money with free-cooling. High temperatures are not harmless, but are much less significant than other factors.
That last finding is key to why the cloud clobbers current array products. It is good for global warming and good for the bottom line.
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I was able to recover the data from a workmate’s (home) HD by installing the control board from another HD by the same mfg and built in the same year but had double the capacity.
There has to be (clean) air inside to float the heads just above the disks without any head crashes.
Wow. That’s cool. I bet that that is what they do when you pay someone to recover a hard drive (or the FBI does it).
Usually the firmware is different and it is tuned to the drive that it is mounted on.
However, the way they double capacity is to simply stack more more platters in the drive. So it makes sense that it would work.
I’ll have to remember that.
I had a person do a complete format and re-install of Windows then turn to me and ask “Where are my files?”. I figured if they were smart enough to do that, they should know the answer.
The way to recover a hard drive is from the backup
Depends. It wouldn't even spin up no matter what I did before the board swap, so I bought a used drive at a computer store that was big on parting out older computers.
That’s an old trick that often works. Transplant the correct logic board onto an alleged crashed beyond repair hard drive. You can buy the logic board on ebay attached to a hard drive...
How often is this all that that data retrieval companies do. 70% of the time???
That was smart. :)
Lol. Yup. But few people back up.
Bookmark for later and thanks!
More on these swaps>>>> http://www.zdnet.com/article/a-word-of-warning-on-hard-disk-recovery-by-swapping-logic-boards/#!
I have a bat file on my desktop that I punch every now and then. I had it in Scheduled Tasks but it kept hanging up
Lol.
Good to know. Thanks!
Me neither: what happens when another 9/11 comes and you lose access to everything?
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