You are here

Don't mix Direct I/O with Concurrent I/O on oracle datafiles FS

This is and important oracle note to take in account when using CIO, posted in the itrc, it says you shouldn't use them together, I haven't been able to test this out performance wise, if someone has, please comment on the result of your tests, because oracle doesn't always get it right with HP-UX and mount point options...

Oracle Support Doc ID ID 1231869.1

Specifically:
-------------------------
Do not use "-o cio" and "-o mincache=direct,convosync=direct" together. Use either Direct I/O or Concurrent I/O.

Using Direct I/O and Concurrent I/O("-o mincache=direct,convosync=direct,cio") may cause performance regression.
-------------------------

And:
-------------------------
Placing Oracle binaries ($ORACLE_BASE directory) on a filesystem mounted with "cio" may cause data loss and other unexpected problems.
-------------------------

And Finally:
-------------------------
Concurrent IO is not expected to provide a performance benefit over direct IO when used with online and archived redo logs.
-------------------------

So:
- use none of cio,mincahce=direct,convosync=direct on Oracle binares
- use cio on datafiles
- use mincahce=direct,convosync=direct on online/archive redo logs

Unix Systems: 

Add new comment

Filtered HTML

  • Web page addresses and e-mail addresses turn into links automatically.
  • Allowed HTML tags: <a> <em> <strong> <cite> <blockquote> <code> <ul> <ol> <li> <dl> <dt> <dd>
  • Lines and paragraphs break automatically.

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
By submitting this form, you accept the Mollom privacy policy.

Additional uncaught exception thrown while handling exception.

Original

PDOException: SQLSTATE[42000]: Syntax error or access violation: 1142 INSERT command denied to user &#039;dbo229817041&#039;@&#039;217.160.155.192&#039; for table &#039;accesslog&#039;: INSERT INTO {accesslog} (title, path, url, hostname, uid, sid, timer, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] =&gt; Don&amp;#039;t mix Direct I/O with Concurrent I/O on oracle datafiles FS [:db_insert_placeholder_1] =&gt; node/256 [:db_insert_placeholder_2] =&gt; [:db_insert_placeholder_3] =&gt; 54.92.205.251 [:db_insert_placeholder_4] =&gt; 0 [:db_insert_placeholder_5] =&gt; oyJ6fJD3iyc1l78Yjzulh24DttKaaLApylhaySdgq5A [:db_insert_placeholder_6] =&gt; 342 [:db_insert_placeholder_7] =&gt; 1461894131 ) in statistics_exit() (line 90 of /homepages/37/d228974590/htdocs/modules/statistics/statistics.module).

Additional

PDOException: SQLSTATE[42000]: Syntax error or access violation: 1142 INSERT command denied to user &#039;dbo229817041&#039;@&#039;217.160.155.192&#039; for table &#039;watchdog&#039;: INSERT INTO {watchdog} (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9); Array ( [:db_insert_placeholder_0] =&gt; 0 [:db_insert_placeholder_1] =&gt; php [:db_insert_placeholder_2] =&gt; %type: !message in %function (line %line of %file). [:db_insert_placeholder_3] =&gt; a:6:{s:5:&quot;%type&quot;;s:12:&quot;PDOException&quot;;s:8:&quot;!message&quot;;s:934:&quot;SQLSTATE[42000]: Syntax error or access violation: 1142 INSERT command denied to user &amp;#039;dbo229817041&amp;#039;@&amp;#039;217.160.155.192&amp;#039; for table &amp;#039;accesslog&amp;#039;: INSERT INTO {accesslog} (title, path, url, hostname, uid, sid, timer, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] =&amp;gt; Don&amp;amp;#039;t mix Direct I/O with Concurrent I/O on oracle datafiles FS [:db_insert_placeholder_1] =&amp;gt; node/256 [:db_insert_placeholder_2] =&amp;gt; [:db_insert_placeholder_3] =&amp;gt; 54.92.205.251 [:db_insert_placeholder_4] =&amp;gt; 0 [:db_insert_placeholder_5] =&amp;gt; oyJ6fJD3iyc1l78Yjzulh24DttKaaLApylhaySdgq5A [:db_insert_placeholder_6] =&amp;gt; 342 [:db_insert_placeholder_7] =&amp;gt; 1461894131 ) &quot;;s:9:&quot;%function&quot;;s:17:&quot;statistics_exit()&quot;;s:5:&quot;%file&quot;;s:68:&quot;/homepages/37/d228974590/htdocs/modules/statistics/statistics.module&quot;;s:5:&quot;%line&quot;;i:90;s:14:&quot;severity_level&quot;;i:3;} [:db_insert_placeholder_4] =&gt; 3 [:db_insert_placeholder_5] =&gt; [:db_insert_placeholder_6] =&gt; http://www.hpuxtips.es/?q=node/256 [:db_insert_placeholder_7] =&gt; [:db_insert_placeholder_8] =&gt; 54.92.205.251 [:db_insert_placeholder_9] =&gt; 1461894131 ) in dblog_watchdog() (line 157 of /homepages/37/d228974590/htdocs/modules/dblog/dblog.module).