198 karma · joined January 26, 2010
> As an example, volumes that operate with 20 GB or less of modified data since their most recent Amazon EBS snapshot can expect an annual failure rate (AFR) of between 0.1% – 0.5%, where failure refers to a complete loss of the volume. This compares with commodity hard disks that will typically fail with an AFR of around 4%, making EBS volumes 10 times more reliable than typical commodity disk drives.
Nowhere within that does it say 0.00% failure rate, and later in the page they even describe how to mitigate the risk of losing data due to disk failure using snapshots, mirrored across availability zones.
I guess I understand (begrudgingly) the necessity to memorize something for a high school math test where you don't have the resources at your disposal to actually find the answers yourself, but in the "real world" where finding the information you're looking for is so quick and inexpensive, it seems like a waste to invest in something that might not be necessary. (Also, for some people who don't have the skills to think through solving those problems on their own, it could be a pretty big disservice.)
I can't even begin to remember how many constants, dates, formulas, names, etc. that I've memorized for a test and then promptly forgot.
>>> class Foo(object):
... def __do_something(self):
... print 'something was done'
...
>>> f = Foo()
>>> f.__do_something()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'Foo' object has no attribute '__do_something'
>>> f._Foo__do_something()
something was done