I will try to investigate further with 10046(for wait events) and truss(for system calls) to come out with a valid test result.
Cheers Dimitre
-- -- Original Message -- -- From: "Radoulov, Dimitre" <cichomitiko@(protected)> To: <kevinc@(protected)>; <oracle-l@(protected)> Sent: Thursday, June 23, 2005 7:35 PM Subject: Re: Q: Filesystem choice for log_archive_dest
> It's a very busy critical production system. When we saw the "cannot > allocate new log" messages, we increased the redo logs from 8x256Mb to > 16x256Mb and the messages disappeared. But our analysis was: the only > thing changed was the direct IO activation, we've never had this problems > before, the load appeared to be the same(it's hard to measure, it's a > mobile phone company with all those SMS services). So now I'm trying to > find the technical explanation of why one could need a direct IO > filesystem for the archived log files. > And there is another thing, that made me post the question: yesterday we > had to run a report query from sqlplus and guess what: the first person > ran the report spooling under the OFA's filesystem, the result was > ORA-01555 (See ORA-01555.ora-code.com) after 3h! And the second, me, ran the same query(same execution > plan!) spooling on the host's local filesystem - successfully in 15min ... > So, we ran another test today with another query, the results: spooling on > the direct IO filesystem: 30min, on the local filesystem: 49s. > > > > Thanks > Dimitre > > > -- -- Original Message -- -- > From: "Kevin Closson" <kevinc@(protected)> > To: <oracle-l@(protected)> > Sent: Thursday, June 23, 2005 6:21 PM > Subject: RE: Q: Filesystem choice for log_archive_dest > > >> >> >So I was wondering, could the direct IO be beneficial for the >> log_archive_dest filesystem in some cases? >> >> yep...see my last post. This just needs tuning. how many >> online logs do you have and what size are they? >> >> -- >> http://www.freelists.org/webpage/oracle-l >
