On Mon, Mar 18, 2013 at 1:31 PM, Greg Smith <g...@2ndquadrant.com> wrote: > On 3/18/13 10:52 AM, Bruce Momjian wrote: >> >> With a potential 10-20% overhead, I am unclear who would enable this at >> initdb time. > > > If you survey people who are running PostgreSQL on "cloud" hardware, be it > Amazon's EC2 or similar options from other vendors, you will find a high > percentage of them would pay quite a bit of performance to make their > storage more reliable. To pick one common measurement for popularity, a > Google search on "ebs corruption" returns 17 million hits. To quote one of > those, Baron Schwartz of Percona talking about MySQL on EC2:> > "BTW, I have seen data corruption on EBS volumes. It’s not clear whether it > was InnoDB’s fault (extremely unlikely IMO), the operating system’s fault, > EBS’s fault, or something else."
Clarification, because I think this assessment as delivered feeds some unnecessary FUD about EBS: EBS is quite reliable. Presuming that all noticed corruptions are strictly EBS's problem (that's quite a stretch), I'd say the defect rate falls somewhere in the range of volume-centuries. I want to point this out because I think EBS gets an outsized amount of public flogging, and not all of it is deserved. My assessment of the caustion at hand: I care about this feature not because EBS sucks more than anything else by a large degree, but because there's an ever mounting number of EBS volumes whose defects are under the responsibility of comparatively few individuals. -- fdr -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
