gnuoytr@xxxxxxx wrote:
Sufficiently bulletproof flash SSD exist and have for years, but their names are not well known (no one on this thread has 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@xxxxxxxxxxxxxxx www.2ndQuadrant.us -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
