You are only *half* right, I fear.
Actually, at least one of -- and perhaps both -- MetaLink and Werner describe more or less the same caveat, that is: applications *other* than Oracle may be responsible for the non-zero counts in slabinfo.
But here's the half where you're wrong. (Or at least, not completely "right".) Those hypothetical "other" applications can just as easily be resposibly for the *increases* in the slabinfo stats as they are they would be for "non-zero" values. After all, those values had to increase from zero *some* *time*, didn't they. ;-)
Anyway, you are correct about this: I am still unaware of a simple way to prove *conclusively* that a database is actually using Asynch I/O. But (on a good day) I now at least know how to prove that it is *not*. (Or at least that *no* databases *are*. Sadly, multiple database on the same host muddy the water even more.)
If anybody out there can tell me of a simple (and reliable) test that *proves* a database is using Asynch I/O, I'd like to hear about it...
In the meantime, it has (happily) met my purposes to be able to prove the negative.
Mark Brinsmead wrote,on my timestamp of 28/07/2006 1:39 PM:
> (Almost) just for chuckles, I opened an SR with Oracle support, asking > questions like "how can > I test whether my DB is doing Asynch I/O on Linux?" and "knowing that > Asynch I/O is unsupported, > what are the risks of doing so anyway?". After almost two weeks, the > questions are unanswered, > even though I was able to answer them myself with less than an hour of > surfing Metalink and Google.
yes, there is a note in metaclick explaining how to check. But it's not complete, neither is werner's site: you check for those counters in /proc/slabinfo being non-zero *AND* changing in value when you startup Oracle! There might be *other* software around already using aio and just having them as non-zero is not enough to say Oracle is using it.
-- Cheers Nuno Souto in (finally) sunny Sydney, Australia dbvision@xxxxxxxxxxxx -- http://www.freelists.org/webpage/oracle-l
-- Cheers, -- Mark Brinsmead Staff DBA, The Pythian Group http://www.pythian.com/blogs