Re: 7.3 vs 7.4 performance

In an attempt to throw the authorities off his trail, csmanioto(at)uol(dot)com(dot)br ("Carlos Eduardo Smanioto") transmitted:
>> I did some heavy-transaction-oriented tests recently on somewhat
>> heftier quad-Xeon hardware, and found little difference between 2.4
>> and 2.6, and a small-but-quite-repeatable advantage with FreeBSD
>> 4.9. Now, I'm quite sure my load was rather different from yours,
>> but I find the claim of doubling of speed rather surprising.
>
> What's the type of File System you used in the Linux? I am wanting
> to know which is the operational system better for PostgreSQL:
> FreeBSD versus Linux 2.6.

On the Linux box in question, I was using JFS, which has had the mixed
reviews, lately, that on the one hand, it _appears_ to be a tad faster
than all the others, but that has been, on the other hand, associated
with systems hanging up and crashing, under load.

The latter bit is a _really_ big caveat. On that particular machine,
I have a nicely repeatable "test case" where I can do a particular set
of "system load" that consistently takes the system down, to the point
of having to hit the "big red button." If I could point to a clear
reason why it happens, I'd be a much happier camper. As it stands, it
is a bit nebulous whether the problem is:
a) Hardware drivers,
b) Flakey hardware (which Linux 2.6.1 copes with a lot better than
2.4!),
c) Flakey 2.4 kernel,
d) Problem with JFS,
e) Something else not yet identified as a plausible cause.

If I could say, "Oh, it's an identified bug in the Frobozz RAID
controller drivers, and was fixed in 2.6.0-pre-17", that would help
allay the suspicion that the problem could be any of the above.
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