<div dir="ltr">Hi OCFS2 forum<br>A few things: <br>(i) thanks for your support of OCFS2 on this forum <br>(ii) the advice I received August 24 to run elevator=deadline io scheduling seems to have helped - there have been no unexpected reboots since then <br>
(iii) we did however have a crash last night on the same RHEL AS4 server (running ocfs2 1.2.9-1) -the crash may be unrelated to ocfs2 but I thought I'd run it past you anyway - here is a copy of a post I made to a linux forum:<br>
<br><i>Last night one of our Linux servers (running RHEL AS4, kernel 2.6.9-42.0.2.ELsmp) crashed. The server is part of a four node ocfs2 1.2.9-1 cluster. After the crash I believe the server needed to be manually restarted. <br>
<br>
I have cut the following out of /var/log/messages event log:<br>
Sep 23 19:15:33 ImageInt1 sshd(pam_unix)[10011]: session opened for user root by root(uid=0)<br>
Sep 23 22:31:04 ImageInt1 kernel: Assertion failure in
do_get_write_access() at fs/jbd/transaction.c:693:
"handle->h_buffer_credits > 0"<br>
Sep 23 22:31:04 ImageInt1 kernel: ----------- [cut here ] --------- [please bite here ] ---------<br>
Sep 23 22:31:06 ImageInt1 kernel: Kernel BUG at transaction:693<br>
Sep 23 22:31:06 ImageInt1 kernel: invalid operand: 0000 [1] SMP<br>
Sep 23 22:31:06 ImageInt1 kernel: CPU 1<br>
Sep 23 22:49:51 ImageInt1 syslogd 1.4.1: restart.<br><br>
I googled on internet for the assertion failure and found one report saying it is a bug in the code, but there was no fix mentioned.<br></i><br>As always, any help is appreciated<br><br>regards<br>Derek<br><br>####################################################<br>
<br><h1>[Ocfs2-users] ocfs2 issue? : unexplained reboots of RHEL 4 server (kernel:2.6.9-42.0.2.ELs)</h1>
<b>Derek Hazell</b>
<a href="mailto:ocfs2-users%40oss.oracle.com?Subject=%5BOcfs2-users%5D%20ocfs2%20issue%3F%20%3A%20unexplained%20reboots%20of%20RHEL%204%0A%09server%20%28kernel%3A2.6.9-42.0.2.ELs%29&In-Reply-To=48B03D9F.7030707%40oracle.com" title="[Ocfs2-users] ocfs2 issue? : unexplained reboots of RHEL 4 server (kernel:2.6.9-42.0.2.ELs)">derek.hazell at gmail.com
</a><br>
<i>Sun Aug 24 04:08:01 PDT 2008</i>
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<pre>Hi Sunil,<br>I checked the grub.conf file on the machine that reboots and there is no<br>(deadline) reference to the io scheduler. I will check when back at work on<br>Monday, but I suspect that we are just using the default io scheduler which<br>
would be cfq.<br><br>Just to briefly elaborate, our ocfs2 cluster consists of three nodes (one<br>node (or its backup) mounts the ocfs2 filesystem read/write, while two other<br>nodes mount the ocfs2 read only. It is always the read/write node that<br>
automatically reboots (fences as we know now) (though sometimes but not<br>always the other systems need to be rebooted to get the system working<br>properly.) The problem could be load-related but it is difficult to be sure.<br>
<br>I will discuss with my colleagues about whether to try the deadline option<br>and/or set up a private network for the ocfs2 members. The deadline option<br>is very easy to try (involving a small change to the grub.conf, and a<br>
reboot), while setting up the private network is a little bit more work but<br>not hard.<br>.<br>rgds<br>Derek<br><br>2008/8/24 Sunil Mushran <<a href="http://oss.oracle.com/mailman/listinfo/ocfs2-users">sunil.mushran at oracle.com</a>><br>
<br>><i> Which io scheduler are you using? On el4, it is best to use deadline.<br></i>><i> cfq is the default. Check the faq for details on using deadline.<br></i>><i><br></i>><i> Derek Hazell wrote:<br></i>><i><br>
</i></pre><br clear="all"><br>-- <br> best wishes<br><br>Derek<br><br><br><br>Psalm 71:14 "But as for me, I will always have hope; I will praise you more and more". (NIV)<br>########################<br>new home ph: 02-9701-0841<br>
new mobile ph: 0458-588-821<br>(or +61-458-588-821 from overseas)<br>email : <a href="mailto:derek.hazell@gmail.com">derek.hazell@gmail.com</a><br>skype : dereklife2005<br>msn : <a href="mailto:derek_hazell@yahoo.com">derek_hazell@yahoo.com</a><br>
yahoo messenger : derek_hazell<br>########################<br>
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