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

Error Condition

A Virtuoso transaction log file may fail to replay, with an error of the form:

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

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

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 dd command; Windows users must first install WinDD or 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 trx file.
   

   
   mv virtuoso.trx old.trx
   

   
   
2. Use the dd to create a truncated copy of the file. The count value should match that shown for Error at offset value.
   

   
   dd if=old.trx of=new.trx bs=1 count=13205546
   

   
   Output will look like this.
   

   
   13205546+0 records in
   13205546+0 records out
   

   
   
3. Now move the truncated file into place.
   

   
   mv new.trx virtuoso.trx
   

   
   
4. Then restart Virtuoso with the truncated transaction log.
   

   
   virtuoso-iodbc-t -f
   

   
   Stopping and restarting Virtuoso as normal should now succeed.

Replication Cluster Deployments of Commercial Edition

Elastic Cluster Deployments of Commercial Edition