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		<title>Memory repair glitch 16.02.2017 - Revision history</title>
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		<updated>2026-05-20T11:14:31Z</updated>
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		<id>http://stab.st-andrews.ac.uk/wiki/index.php?title=Memory_repair_glitch_16.02.2017&amp;diff=1137&amp;oldid=prev</id>
		<title>Rf: Created page with &quot;= Introduction =  As detailed in the hardware section, there has been ongoing memory correction warnings for something like an entire year now.  In December, I had finally got...&quot;</title>
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				<updated>2017-02-17T18:08:50Z</updated>
		
		<summary type="html">&lt;p&gt;Created page with &amp;quot;= Introduction =  As detailed in the hardware section, there has been ongoing memory correction warnings for something like an entire year now.  In December, I had finally got...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;= Introduction =&lt;br /&gt;
&lt;br /&gt;
As detailed in the hardware section, there has been ongoing memory correction warnings for something like an entire year now.&lt;br /&gt;
&lt;br /&gt;
In December, I had finally got around to locating the issue and it seemed to concern the same DIMM,  whose location had to be deduced from various tools. Afterwards however, I was sure of it, but needed to delay because due to heavy workloads.&lt;br /&gt;
&lt;br /&gt;
Finally mid February, the processing workload came down a little, so a re-start was forced on the users.&lt;br /&gt;
&lt;br /&gt;
== Glitch ==&lt;br /&gt;
&lt;br /&gt;
The memory swap was smooth but the marvin node seemed to hang on a file system check.&lt;br /&gt;
&lt;br /&gt;
= Key learnings =&lt;br /&gt;
&lt;br /&gt;
* Absolutely keep non-system filesystems commented-out in /etc/fstab&lt;br /&gt;
* when wanting to mount or un-mount, de-comment these lines again. Yes, this is a very manual method, but this is critical issue.&lt;br /&gt;
* bring nodes down before taking down marvin.&lt;br /&gt;
* the appending of &amp;#039;&amp;#039;&amp;#039;int=/bin/bash&amp;#039;&amp;#039;&amp;#039; or &amp;#039;&amp;#039;&amp;#039;emergency&amp;#039;&amp;#039;&amp;#039; to the kernel boot up options does not work. The system instead hangs (apparently) on &amp;#039;&amp;#039;&amp;#039;dracut&amp;#039;&amp;#039;&amp;#039;. This actually is very poor. An emergency mode should need as little as possible to work.&lt;br /&gt;
* the virtual media functions on marvin&amp;#039;s IPMI is not useable, it fails to upload the images correctly both via web interface and IPMI View. Aggravatingly, they appear to load ... but never complete.&lt;br /&gt;
&lt;br /&gt;
= Critical issues =&lt;br /&gt;
&lt;br /&gt;
The chief critical issue seems to be that of the de-activation of storage LVM, and the inability of the Red Hat boot-up procedure to deal with it.&lt;br /&gt;
&lt;br /&gt;
The boot-up procedure hangs, not at the beginning, but quite close to the end of the procedure, semmingly not know what to do with a deactivated LVM.&lt;br /&gt;
&lt;br /&gt;
Why does the storage LVM de-activate and not the others? This issue is still not clear.&lt;br /&gt;
&lt;br /&gt;
The upshot is that the /storage system should never be set for mounting on boot but rather should be mounted manually afterwards. This requires off-on-off commenting in the &amp;#039;&amp;#039;&amp;#039;/etc/fstab&amp;#039;&amp;#039;&amp;#039; file.&lt;/div&gt;</summary>
		<author><name>Rf</name></author>	</entry>

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