diff --git a/contrib/pg_upgrade/check.c b/contrib/pg_upgrade/check.c
new file mode 100644
index fa4ef8d..528b674
*** a/contrib/pg_upgrade/check.c
--- b/contrib/pg_upgrade/check.c
*************** issue_warnings(char *sequence_script_fil
*** 170,176 ****
  					  "--no-psqlrc --port %d --username \"%s\" "
  					  "-f \"%s\" --dbname template1 >> \"%s\"" SYSTEMQUOTE,
  					  new_cluster.bindir, new_cluster.port, os_info.user,
! 					  sequence_script_file_name, log_opts.filename);
  			unlink(sequence_script_file_name);
  			check_ok();
  		}
--- 170,176 ----
  					  "--no-psqlrc --port %d --username \"%s\" "
  					  "-f \"%s\" --dbname template1 >> \"%s\"" SYSTEMQUOTE,
  					  new_cluster.bindir, new_cluster.port, os_info.user,
! 					  sequence_script_file_name, log_opts.filename2);
  			unlink(sequence_script_file_name);
  			check_ok();
  		}
diff --git a/contrib/pg_upgrade/option.c b/contrib/pg_upgrade/option.c
new file mode 100644
index 1793bb3..32bd3b8
*** a/contrib/pg_upgrade/option.c
--- b/contrib/pg_upgrade/option.c
*************** parseCommandLine(int argc, char *argv[])
*** 192,199 ****
  			pg_log(PG_FATAL, "cannot write to log file %s\n", log_opts.filename);
  	}
  	else
! 		log_opts.filename = strdup(DEVNULL);
  
  	/* if no debug file name, output to the terminal */
  	if (log_opts.debug && !log_opts.debug_fd)
  	{
--- 192,206 ----
  			pg_log(PG_FATAL, "cannot write to log file %s\n", log_opts.filename);
  	}
  	else
! 		log_opts.filename = pg_strdup(DEVNULL);
  
+ 	/* WIN32 files do not accept writes from multiple processes */
+ #ifndef WIN32
+ 	log_opts.filename2 = pg_strdup(log_opts.filename);
+ #else
+ 	log_opts.filename2 = pg_strdup(DEVNULL);
+ #endif
+ 		
  	/* if no debug file name, output to the terminal */
  	if (log_opts.debug && !log_opts.debug_fd)
  	{
diff --git a/contrib/pg_upgrade/pg_upgrade.c b/contrib/pg_upgrade/pg_upgrade.c
new file mode 100644
index efa5c0f..4912f77
*** a/contrib/pg_upgrade/pg_upgrade.c
--- b/contrib/pg_upgrade/pg_upgrade.c
*************** prepare_new_cluster(void)
*** 193,200 ****
  	prep_status("Analyzing all rows in the new cluster");
  	exec_prog(true,
  			  SYSTEMQUOTE "\"%s/vacuumdb\" --port %d --username \"%s\" "
! 			  "--all --analyze >> %s 2>&1" SYSTEMQUOTE,
! 	  new_cluster.bindir, new_cluster.port, os_info.user, log_opts.filename);
  	check_ok();
  
  	/*
--- 193,200 ----
  	prep_status("Analyzing all rows in the new cluster");
  	exec_prog(true,
  			  SYSTEMQUOTE "\"%s/vacuumdb\" --port %d --username \"%s\" "
! 			  "--all --analyze >> \"%s\" 2>&1" SYSTEMQUOTE,
! 	  new_cluster.bindir, new_cluster.port, os_info.user, log_opts.filename2);
  	check_ok();
  
  	/*
*************** prepare_new_cluster(void)
*** 206,213 ****
  	prep_status("Freezing all rows on the new cluster");
  	exec_prog(true,
  			  SYSTEMQUOTE "\"%s/vacuumdb\" --port %d --username \"%s\" "
! 			  "--all --freeze >> %s 2>&1" SYSTEMQUOTE,
! 	  new_cluster.bindir, new_cluster.port, os_info.user, log_opts.filename);
  	check_ok();
  
  	get_pg_database_relfilenode(&new_cluster);
--- 206,213 ----
  	prep_status("Freezing all rows on the new cluster");
  	exec_prog(true,
  			  SYSTEMQUOTE "\"%s/vacuumdb\" --port %d --username \"%s\" "
! 			  "--all --freeze >> \"%s\" 2>&1" SYSTEMQUOTE,
! 	  new_cluster.bindir, new_cluster.port, os_info.user, log_opts.filename2);
  	check_ok();
  
  	get_pg_database_relfilenode(&new_cluster);
*************** prepare_new_databases(void)
*** 245,251 ****
  			  "--no-psqlrc --port %d --username \"%s\" "
  			  "-f \"%s/%s\" --dbname template1 >> \"%s\"" SYSTEMQUOTE,
  			  new_cluster.bindir, new_cluster.port, os_info.user, os_info.cwd,
! 			  GLOBALS_DUMP_FILE, log_opts.filename);
  	check_ok();
  
  	/* we load this to get a current list of databases */
--- 245,251 ----
  			  "--no-psqlrc --port %d --username \"%s\" "
  			  "-f \"%s/%s\" --dbname template1 >> \"%s\"" SYSTEMQUOTE,
  			  new_cluster.bindir, new_cluster.port, os_info.user, os_info.cwd,
! 			  GLOBALS_DUMP_FILE, log_opts.filename2);
  	check_ok();
  
  	/* we load this to get a current list of databases */
*************** create_new_objects(void)
*** 276,282 ****
  			  "--no-psqlrc --port %d --username \"%s\" "
  			  "-f \"%s/%s\" --dbname template1 >> \"%s\"" SYSTEMQUOTE,
  			  new_cluster.bindir, new_cluster.port, os_info.user, os_info.cwd,
! 			  DB_DUMP_FILE, log_opts.filename);
  	check_ok();
  
  	/* regenerate now that we have objects in the databases */
--- 276,282 ----
  			  "--no-psqlrc --port %d --username \"%s\" "
  			  "-f \"%s/%s\" --dbname template1 >> \"%s\"" SYSTEMQUOTE,
  			  new_cluster.bindir, new_cluster.port, os_info.user, os_info.cwd,
! 			  DB_DUMP_FILE, log_opts.filename2);
  	check_ok();
  
  	/* regenerate now that we have objects in the databases */
*************** copy_clog_xlog_xid(void)
*** 324,330 ****
  	exec_prog(true, SYSTEMQUOTE "\"%s/pg_resetxlog\" -l %u,%u,%u \"%s\" >> \"%s\" 2>&1" SYSTEMQUOTE,
  			  new_cluster.bindir, old_cluster.controldata.chkpnt_tli,
  			old_cluster.controldata.logid, old_cluster.controldata.nxtlogseg,
! 			  new_cluster.pgdata, log_opts.filename);
  	check_ok();
  }
  
--- 324,330 ----
  	exec_prog(true, SYSTEMQUOTE "\"%s/pg_resetxlog\" -l %u,%u,%u \"%s\" >> \"%s\" 2>&1" SYSTEMQUOTE,
  			  new_cluster.bindir, old_cluster.controldata.chkpnt_tli,
  			old_cluster.controldata.logid, old_cluster.controldata.nxtlogseg,
! 			  new_cluster.pgdata, log_opts.filename2);
  	check_ok();
  }
  
diff --git a/contrib/pg_upgrade/pg_upgrade.h b/contrib/pg_upgrade/pg_upgrade.h
new file mode 100644
index 4729ac3..df884bd
*** a/contrib/pg_upgrade/pg_upgrade.h
--- b/contrib/pg_upgrade/pg_upgrade.h
*************** typedef struct
*** 199,204 ****
--- 199,214 ----
  typedef struct
  {
  	char	   *filename;		/* name of log file (may be /dev/null) */
+ 	/*
+ 	 * WIN32 files do not accept writes from multiple processes
+ 	 *
+ 	 * On Win32, we can't send both pg_upgrade output and command output to the
+ 	 * same file because we get the error: "The process cannot access the file
+ 	 * because it is being used by another process." so we have to send all
+ 	 * other output to 'nul'.  Therefore, we set this to DEVNULL on Win32, and
+ 	 * it equals 'filename' on all other platforms.
+ 	 */
+ 	char	   *filename2;
  	FILE	   *fd;				/* log FILE */
  	bool		debug;			/* TRUE -> log more information */
  	FILE	   *debug_fd;		/* debug-level log FILE */
diff --git a/contrib/pg_upgrade/server.c b/contrib/pg_upgrade/server.c
new file mode 100644
index 59eaad9..17231da
*** a/contrib/pg_upgrade/server.c
--- b/contrib/pg_upgrade/server.c
*************** start_postmaster(ClusterInfo *cluster)
*** 147,165 ****
  	bool		exit_hook_registered = false;
  	int			pg_ctl_return = 0;
  
- #ifndef WIN32
- 	char	   *output_filename = log_opts.filename;
- #else
- 
- 	/*
- 	 * On Win32, we can't send both pg_upgrade output and pg_ctl output to the
- 	 * same file because we get the error: "The process cannot access the file
- 	 * because it is being used by another process." so we have to send all
- 	 * other output to 'nul'.
- 	 */
- 	char	   *output_filename = DEVNULL;
- #endif
- 
  	if (!exit_hook_registered)
  	{
  #ifdef HAVE_ATEXIT
--- 147,152 ----
*************** start_postmaster(ClusterInfo *cluster)
*** 180,190 ****
  	snprintf(cmd, sizeof(cmd),
  			 SYSTEMQUOTE "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" "
  			 "-o \"-p %d %s\" start >> \"%s\" 2>&1" SYSTEMQUOTE,
! 			 cluster->bindir, output_filename, cluster->pgdata, cluster->port,
  			 (cluster->controldata.cat_ver >=
  			  BINARY_UPGRADE_SERVER_FLAG_CAT_VER) ? "-b" :
  			 "-c autovacuum=off -c autovacuum_freeze_max_age=2000000000",
! 			 log_opts.filename);
  
  	/*
  	 * Don't throw an error right away, let connecting throw the error because
--- 167,177 ----
  	snprintf(cmd, sizeof(cmd),
  			 SYSTEMQUOTE "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" "
  			 "-o \"-p %d %s\" start >> \"%s\" 2>&1" SYSTEMQUOTE,
! 			 cluster->bindir, log_opts.filename2, cluster->pgdata, cluster->port,
  			 (cluster->controldata.cat_ver >=
  			  BINARY_UPGRADE_SERVER_FLAG_CAT_VER) ? "-b" :
  			 "-c autovacuum=off -c autovacuum_freeze_max_age=2000000000",
! 			 log_opts.filename2);
  
  	/*
  	 * Don't throw an error right away, let connecting throw the error because
*************** stop_postmaster(bool fast)
*** 221,233 ****
  	const char *bindir;
  	const char *datadir;
  
- #ifndef WIN32
- 	char	   *output_filename = log_opts.filename;
- #else
- 	/* See comment in start_postmaster() about why win32 output is ignored. */
- 	char	   *output_filename = DEVNULL;
- #endif
- 
  	if (os_info.running_cluster == &old_cluster)
  	{
  		bindir = old_cluster.bindir;
--- 208,213 ----
*************** stop_postmaster(bool fast)
*** 244,251 ****
  	snprintf(cmd, sizeof(cmd),
  			 SYSTEMQUOTE "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" %s stop >> "
  			 "\"%s\" 2>&1" SYSTEMQUOTE,
! 			 bindir, output_filename, datadir, fast ? "-m fast" : "",
! 			 output_filename);
  
  	exec_prog(fast ? false : true, "%s", cmd);
  
--- 224,231 ----
  	snprintf(cmd, sizeof(cmd),
  			 SYSTEMQUOTE "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" %s stop >> "
  			 "\"%s\" 2>&1" SYSTEMQUOTE,
! 			 bindir, log_opts.filename2, datadir, fast ? "-m fast" : "",
! 			 log_opts.filename2);
  
  	exec_prog(fast ? false : true, "%s", cmd);