Re: Data Corruption in case of abrupt failure

Quoting Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:

> Stephen Robert Norris <srn(at)commsecure(dot)com(dot)au> writes:
> > On Wed, 2004-03-03 at 23:27, satish satish wrote:
> >> I am trying to do some reliability tests on postgre SQL. I have
> >> use-case where the power can go off abruptly. I initiated 10,000
> >> insert operations and pulled out the cable in the middle. I had
> >> auto-commit option turned on. I observed 2 out of 5 times the tables
> >> were totally corrupted and could not read any data whereas 3 times I
> >> was able to read the data which was inserted.
>
> > We'll need more information - what OS and what version of PostgreSQL at
> > the least.
>
> I doubt this has anything to do with either the OS or the Postgres
> version. My money is on IDE drives with write cache enabled.
> Use drives that don't lie about write completion, and you'll be in
> good shape.
>
> regards, tom lane
>
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I've read threads like this before and because I've never lost data on servers
with IDE drives after doing some basic torture tests (e.g. pulling the plug in
the middle of an update et al), I don't think I've paid close enough attention.

Is there some definite way someone can test their IDE drives so see whether or
not they are "lying" about write completions? Perhaps someone somewhere has a
list of drives that are known to exhibit this problem- a IDE drive blacklist of
sorts?

--
Keith C. Perry, MS E.E.
Director of Networks & Applications
VCSN, Inc.
http://vcsn.com

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