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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext">Hi Arun,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext">If you happen to reboot when Mnesia is writing out its logfile, it can become corrupt (and lose data). We fight this issue on embedded devices a lot.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext">Look “Configuration Parameters” section here:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"><a href="http://erlang.org/doc/man/mnesia.html#id69584">http://erlang.org/doc/man/mnesia.html#id69584</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext">You will want to set
</span><span style="font-family:Courier;color:#1A1A1A;background:#F3F3F3">dump_log_update_in_place</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"> to false. This will make it write out the table to a new file, and rename
it the very end. <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext">One other option to look at is
</span><span style="font-family:Courier;color:#1A1A1A;background:#F3F3F3">dump_log_time_threshold</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"> to change how often items are flushed to disk. For configuration data,
you can likely set this to a few seconds.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext">These options can be set via the sys.config file as well<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext">Mike<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"> erlang-questions-bounces@erlang.org [mailto:erlang-questions-bounces@erlang.org]
<b>On Behalf Of </b>Arun<br>
<b>Sent:</b> Tuesday, November 21, 2017 10:16 PM<br>
<b>To:</b> erlang-questions@erlang.org<br>
<b>Subject:</b> [erlang-questions] Mnesia deleting log file<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p>Dear all,<o:p></o:p></p>
<p>I've a program written in erlang which uses Mnesia application as the database application. I've a table created by name "configuration_table" which stores<o:p></o:p></p>
<p>certain configurations that need to be persistent. Occasionally, whenever I restart my program the following error is thrown by mnesia and I end up losing<o:p></o:p></p>
<p>all the persistent configurations. <o:p></o:p></p>
<p>I've searched about this problem in the erlang documentation and all it tells is "Node not running". What could be the probable cause for this problem<o:p></o:p></p>
<p>and how do I fix it?<o:p></o:p></p>
<p>Mnesia('<a href="mailto:ommp82_plus@10.1.4.16">test@10.1.4.16</a>'): Data may be missing, Corrupt logfile deleted: "/home/utl/mnesia_database/configuration_table.DCL", {node_not_running,
<br>
'test<a href="mailto:ommp82_plus@10.1.4.16">@10.1.4.16</a>'} <o:p></o:p></p>
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