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---+ How do I recover from "Invalid log entry in replay" when transaction log is being replayed during server start?

%TOC%

---++ Error Condition

A Virtuoso transaction log file may fail to replay, with an error of the form:
<verbatim>
11:42:57 Invalid log entry in replay. Delete transaction log virtuoso.trx or truncate at point of error. 
Valid data may exist after this record. A log record begins with bytes 193 188 5 188 0. Error at offset 13205546
11:42:57 Searching for the next valid header signature starting at 13205547
11:42:57 No valid looking header found.
11:42:57 Server exiting
</verbatim>

Resolution of this error varies with the kind of Virtuoso server you're running.

---++ Recovery Methods

---+++ Single-Server Deployments of both Open Source and Commercial Edition

<i><b>WARNING:</b> Do not use this recovery method on Cluster Deployments of Commercial Edition.</i>

This can be recovered by truncating to the transaction log to the reported error offset.  

Users on Unix-like OS can use the built-in <code>dd</code> command; Windows users must first install [[http://sourceforge.net/projects/windd/][WinDD]] or [[http://www.cygwin.com/][cygwin]] to get the same functionality.

Given the error above, the recovery steps on a Unix-like OS would look like those below.
   1 Rename the bad <code>trx</code> file.
<verbatim>
mv virtuoso.trx old.trx
</verbatim>
   1 Use the <code>dd</code> to create a truncated copy of the file.  The <code>count</code> value should match that shown for <code>Error at offset <i>value</i></code>.
<verbatim>
dd if=old.trx of=new.trx bs=1 count=13205546
</verbatim>
Output will look like this.
<verbatim>
13205546+0 records in
13205546+0 records out
</verbatim>
   1 Now move the truncated file into place.
<verbatim>
mv new.trx virtuoso.trx
</verbatim>
   1 Then restart Virtuoso with the truncated transaction log.
<verbatim>
virtuoso-iodbc-t -f
</verbatim>

Stopping and restarting Virtuoso as normal should now succeed.

---+++ Replication Cluster Deployments of Commercial Edition

<i>Recovery instructions coming soon!  Until then, please [[http://support.openlinksw.com/support/online-support.vsp][contact Support for assistance]].</i>

---+++ Elastic Cluster Deployments of Commercial Edition

<i>Recovery instructions coming soon!  Until then, please [[http://support.openlinksw.com/support/online-support.vsp][contact Support for assistance]].</i>