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 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
>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?
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