gnuoytr@rcn.com wrote:
> Sufficiently bulletproof flash SSD exist and have for years, but their names are not well known (no one on this
threadhas named any)
The models perceived as bulletproof are the really dangerous ones to
deploy. First, people let their guard down and stop being as paranoid
as they should be when they use them. Second, it becomes much more
difficult for them to justify buying more than one of the uber-SSD.
That combination makes it easier to go back to having a single copy of
their data, and there's a really bad road to wander down.
The whole idea that kicked off this thread was to enable building
systems cheap enough to allow making more inexpensive copies of the
data. My systems at home for example follow this model to some degree.
There's not a single drive more expensive than $100 to be found here,
but everything important to me is sitting on four of them in two systems
within seconds after I save it. However, even here I've found it worth
dropping enough money for a real battery-backed write cache, to reduce
the odds of write corruption on the more important of the servers. Not
doing so would be a dangerously cheap decision. That's similar to how I
feel about SSDs right now too. You need them to be expensive enough
that corruption is unusual rather than expected after a crash--it's
ridiculous to not spend enough to get something that's not completely
broken by design--while not spending so much that you can't afford to
deploy many of them.
--
Greg Smith 2ndQuadrant US Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com www.2ndQuadrant.us
