diff --git a/Anvil/Tools/Database.pm b/Anvil/Tools/Database.pm
index 5b26766a..6f341595 100644
--- a/Anvil/Tools/Database.pm
+++ b/Anvil/Tools/Database.pm
@@ -2635,6 +2635,202 @@ WHERE
 	return($file_uuid);
 }
 
+=head2 insert_or_update_host_keys
+
+This updates (or inserts) a record in the 'host_keys' table. The C<< host_key_uuid >> UUID will be returned.
+
+If there is an error, an empty string is returned.
+
+Parameters;
+
+=head3 uuid (optional)
+
+If set, only the corresponding database will be written to.
+
+=head3 file (optional)
+
+If set, this is the file name logged as the source of any INSERTs or UPDATEs.
+
+=head3 line (optional)
+
+If set, this is the file line number logged as the source of any INSERTs or UPDATEs.
+
+=head3 host_key_host_uuid (optional, default is Get->host_uuid)
+
+This is the host that the corresponding user and key belong to.
+
+=head3 host_key_public_key (required)
+
+This is the B<<PUBLIC>> key for the user, the full line stored in the user's C<< ~/.ssh/id_rsa.pub >> file.
+
+=head3 host_key_user_name (required)
+
+This is the name of the user that the public key belongs to.
+
+=head3 host_key_uuid (optional)
+
+This is the specific record to update. If not provides, a search will be made to find a matching entry. If found, the record will be updated if one of the values has changed. If not, a new record will be inserted.
+
+=cut
+sub insert_or_update_host_keys
+{
+	my $self      = shift;
+	my $parameter = shift;
+	my $anvil     = $self->parent;
+	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
+	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => $debug, key => "log_0125", variables => { method => "Database->insert_or_update_host_keys()" }});
+	
+	my $uuid                = defined $parameter->{uuid}                ? $parameter->{uuid}                : "";
+	my $file                = defined $parameter->{file}                ? $parameter->{file}                : "";
+	my $line                = defined $parameter->{line}                ? $parameter->{line}                : "";
+	my $host_key_host_uuid  = defined $parameter->{host_key_host_uuid}  ? $parameter->{host_key_host_uuid}  : $anvil->Get->host_uuid;
+	my $host_key_public_key = defined $parameter->{host_key_public_key} ? $parameter->{host_key_public_key} : "";
+	my $host_key_user_name  = defined $parameter->{host_key_user_name}  ? $parameter->{host_key_user_name}  : "";
+	my $host_key_uuid       = defined $parameter->{host_key_uuid}       ? $parameter->{host_key_uuid}       : "";
+	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
+		uuid                => $uuid, 
+		file                => $file, 
+		line                => $line, 
+		host_key_host_uuid  => $host_key_host_uuid, 
+		host_key_public_key => $host_key_public_key, 
+		host_key_user_name  => $host_key_user_name, 
+		host_key_uuid       => $host_key_uuid, 
+	}});
+	
+	if (not $host_key_public_key)
+	{
+		# Throw an error and exit.
+		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_host_keys()", parameter => "host_key_public_key" }});
+		return("");
+	}
+	if (not $host_key_user_name)
+	{
+		# Throw an error and exit.
+		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0020", variables => { method => "Database->insert_or_update_host_keys()", parameter => "host_key_user_name" }});
+		return("");
+	}
+	
+	# If we don't have a UUID, see if we can find one for the given user and host.
+	if (not $host_key_uuid)
+	{
+		my $query = "
+SELECT 
+    host_key_uuid 
+FROM 
+    host_keys 
+WHERE 
+    host_key_user_name = ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_user_name)." 
+AND 
+    host_key_host_uuid = ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_host_uuid)." 
+;";
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
+		
+		my $results = $anvil->Database->query({query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
+		my $count   = @{$results};
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
+			results => $results, 
+			count   => $count, 
+		}});
+		if ($count)
+		{
+			$host_key_uuid = $results->[0]->[0];
+			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_key_uuid => $host_key_uuid }});
+		}
+	}
+	
+	# If I still don't have an host_key_uuid, we're INSERT'ing .
+	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_key_uuid => $host_key_uuid }});
+	if (not $host_key_uuid)
+	{
+		# INSERT
+		$host_key_uuid = $anvil->Get->uuid();
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_key_uuid => $host_key_uuid }});
+		
+		my $query = "
+INSERT INTO 
+    host_keys 
+(
+    host_key_uuid, 
+    host_key_host_uuid, 
+    host_key_public_key, 
+    host_key_user_name, 
+    modified_date 
+) VALUES (
+    ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_uuid).", 
+    ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_host_uuid).", 
+    ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_public_key).", 
+    ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_user_name).", 
+    ".$anvil->data->{sys}{database}{use_handle}->quote($anvil->data->{sys}{database}{timestamp})."
+);
+";
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
+		$anvil->Database->write({query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
+	}
+	else
+	{
+		# Query the rest of the values and see if anything changed.
+		my $query = "
+SELECT 
+    host_key_host_uuid, 
+    host_key_public_key, 
+    host_key_user_name 
+FROM 
+    host_keys 
+WHERE 
+    host_key_uuid = ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_uuid)." 
+;";
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
+		
+		my $results = $anvil->Database->query({query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
+		my $count   = @{$results};
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
+			results => $results, 
+			count   => $count, 
+		}});
+		if (not $count)
+		{
+			# I have a host_key_uuid but no matching record. Probably an error.
+			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0216", variables => { uuid_name => "host_key_uuid", uuid => $host_key_uuid }});
+			return("");
+		}
+		foreach my $row (@{$results})
+		{
+			my $old_host_key_host_uuid  = $row->[0];
+			my $old_host_key_public_key = $row->[1];
+			my $old_host_key_user_name  = $row->[2];
+			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { 
+				old_host_key_host_uuid  => $old_host_key_host_uuid, 
+				old_host_key_public_key => $old_host_key_public_key, 
+				old_host_key_user_name  => $old_host_key_user_name, 
+			}});
+			
+			# Anything change?
+			if (($old_host_key_host_uuid  ne $host_key_host_uuid)  or 
+			    ($old_host_key_public_key ne $host_key_public_key) or 
+			    ($old_host_key_user_name  ne $host_key_user_name))
+			{
+				# Something changed, save.
+				my $query = "
+UPDATE 
+    host_keys 
+SET 
+    host_key_host_uuid  = ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_host_uuid).",  
+    host_key_public_key = ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_public_key).", 
+    host_key_user_name  = ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_user_name).", 
+    modified_date       = ".$anvil->data->{sys}{database}{use_handle}->quote($anvil->data->{sys}{database}{timestamp})." 
+WHERE 
+    host_key_uuid       = ".$anvil->data->{sys}{database}{use_handle}->quote($host_key_uuid)." 
+";
+				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { query => $query }});
+				$anvil->Database->write({query => $query, source => $file ? $file." -> ".$THIS_FILE : $THIS_FILE, line => $line ? $line." -> ".__LINE__ : __LINE__});
+			}
+		}
+	}
+	
+	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => $debug, list => { host_key_uuid => $host_key_uuid }});
+	return($host_key_uuid);
+}
+
 =head2 insert_or_update_hosts
 
 This updates (or inserts) a record in the 'hosts' table. The C<< host_uuid >> UUID will be returned.
diff --git a/Anvil/Tools/Storage.pm b/Anvil/Tools/Storage.pm
index ca81d618..9506586a 100644
--- a/Anvil/Tools/Storage.pm
+++ b/Anvil/Tools/Storage.pm
@@ -504,7 +504,7 @@ sub check_md5sums
 	{
 		# Exit.
 		$exit = 1;
-		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "warn", key => "log_0250", variables => { 
+		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "alert", key => "log_0250", variables => { 
 			file    => $0,
 			old_sum => $anvil->data->{md5sum}{$caller}{start_time},
 			new_sum => $anvil->data->{md5sum}{$caller}{now},
@@ -541,7 +541,7 @@ sub check_md5sums
 		{
 			# Changed.
 			$exit = 1;
-			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "warn", key => "log_0250", variables => { 
+			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "alert", key => "log_0250", variables => { 
 				file    => $module_file,
 				old_sum => $anvil->data->{md5sum}{$module_file}{start_time},
 				new_sum => $anvil->data->{md5sum}{$module_file}{now},
@@ -566,7 +566,7 @@ sub check_md5sums
 		if ($anvil->data->{md5sum}{$file}{start_time} ne $anvil->data->{md5sum}{$file}{now})
 		{
 			$exit = 1;
-			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "warn", key => "log_0250", variables => { 
+			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "alert", key => "log_0250", variables => { 
 				file    => $file,
 				old_sum => $anvil->data->{md5sum}{$file}{start_time},
 				new_sum => $anvil->data->{md5sum}{$file}{now},
diff --git a/cgi-bin/upload.pl b/cgi-bin/upload.pl
index 0b297223..2ec93903 100755
--- a/cgi-bin/upload.pl
+++ b/cgi-bin/upload.pl
@@ -134,7 +134,7 @@ if ($cgi->param())
 else
 {
 	# Why are we here?
-	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, priority => "warn", key => "log_0261", variables => { file => $THIS_FILE }});
+	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, priority => "alert", key => "log_0261", variables => { file => $THIS_FILE }});
 }
 
 exit(0);
diff --git a/share/words.xml b/share/words.xml
index d8449439..c4674df8 100644
--- a/share/words.xml
+++ b/share/words.xml
@@ -572,6 +572,7 @@ The user: [#!variable!user!#]'s SSH key yet has been generated. The output is be
 ====
 		</key>
 		<key name="log_0272">The user: [#!variable!user!#] doesn't appear to have a base SSH directory. Will now create: [#!variable!directory!#].</key>
+		<key name="log_0273">The user: [#!variable!user!#]'s: [#!variable!file!#] file needs to be updated.</key>
 		
 		<!-- Test words. Do NOT change unless you update 't/Words.t' or tests will needlessly fail. -->
 		<key name="t_0000">Test</key>
@@ -838,6 +839,7 @@ Failed to generate an RSA public key for the user: [#!variable!user!#]. The outp
 #!variable!output!#
 ====
 		</key>
+		<key name="error_0058">Failed to backup: [#!variable!file!#], skipping..</key>
 		
 		<!-- These are units, words and so on used when displaying information. -->
 		<key name="unit_0001">Yes</key>
diff --git a/tools/anvil-daemon b/tools/anvil-daemon
index 6a6b6f04..0f38228c 100755
--- a/tools/anvil-daemon
+++ b/tools/anvil-daemon
@@ -50,6 +50,7 @@ use JSON;
 use HTML::Strip;
 use HTML::FromText;
 use Data::Dumper;
+use Text::Diff;
 
 my $THIS_FILE           =  ($0 =~ /^.*\/(.*)$/)[0];
 my $running_directory   =  ($0 =~ /^(.*?)\/$THIS_FILE$/)[0];
@@ -73,6 +74,9 @@ $anvil->Log->secure({set => 1});
 $anvil->Database->connect({debug => 3, check_if_configured => 1});
 $anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 3, secure => 0, key => "log_0132"});
 
+check_ssh_keys($anvil);
+die;
+
 # If I have no databases, sleep for a second and then exit (systemd will restart us).
 if (not $anvil->data->{sys}{database}{connections})
 {
@@ -174,7 +178,7 @@ while(1)
 	# Exit if 'run-once' selected.
 	if ($anvil->data->{switches}{'run-once'})
 	{
-		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "warn", key => "message_0055"});
+		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "alert", key => "message_0055"});
 		$anvil->nice_exit({code => 0});
 	}
 	
@@ -219,7 +223,7 @@ sub handle_periodic_tasks
 		if ((not $anvil->data->{timing}{jobs_running}) && ($anvil->Storage->check_md5sums))
 		{
 			# NOTE: We exit with '0' to prevent systemctl from showing a scary red message.
-			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "warn", key => "message_0014"});
+			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "alert", key => "message_0014"});
 			$anvil->nice_exit({code => 0});
 		}
 		
@@ -253,7 +257,7 @@ sub handle_periodic_tasks
 				if ($failed)
 				{
 					# Something went wrong.
-					$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "warn", key => "log_0254", variables => {
+					$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "alert", key => "log_0254", variables => {
 						directory => $directory,
 					}});
 				}
@@ -311,12 +315,14 @@ sub check_ssh_keys
 	
 	# Get a list of all hosts and IPs we know about. We'll use this to update 
 	
+	# Get a list of machine host keys and user public keys from other machines.
+	get_other_keys($anvil);
 	
 	# Users to check:
 	# root, admin, hacluster
 	foreach my $user ("root", "admin")
 	{
-		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { user => $user }});
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { user => $user }});
 		
 		my $user_home = $anvil->Get->users_home({user => $user});
 		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { user_home => $user_home }});
@@ -331,7 +337,7 @@ sub check_ssh_keys
 		if (not -e $ssh_directory)
 		{
 			# Create it.
-			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, key => "log_0272", variables => { user => $user, directory => $ssh_directory }});
+			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0272", variables => { user => $user, directory => $ssh_directory }});
 			$anvil->Storage->make_directory({
 				directory => $ssh_directory, 
 				user      => $user,
@@ -347,20 +353,20 @@ sub check_ssh_keys
 		
 		my $ssh_private_key_file = $user_home."/.ssh/id_rsa";
 		my $ssh_public_key_file  = $user_home."/.ssh/id_rsa.pub";
-		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
 			ssh_public_key_file  => $ssh_public_key_file,
 			ssh_private_key_file => $ssh_private_key_file, 
 		}});
 		if (not -e $ssh_public_key_file)
 		{
 			# Generate the SSH keys.
-			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, key => "log_0270", variables => { user => $user }});
+			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0270", variables => { user => $user }});
 			
 			my $output = $anvil->System->call({shell_call => $anvil->data->{path}{exe}{'ssh-keygen'}." -t rsa -N \"\" -b 8191 -f ".$ssh_private_key_file});
 			if (-e $ssh_public_key_file)
 			{
 				# Success!
-				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, key => "log_0271", variables => { user => $user, output => $output }});
+				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0271", variables => { user => $user, output => $output }});
 			}
 			else
 			{
@@ -369,11 +375,305 @@ sub check_ssh_keys
 				next;
 			}
 		}
-		
+	
 		# Now read in the key.
 		my $users_public_key =  $anvil->Storage->read_file({file => $ssh_public_key_file});
 		   $users_public_key =~ s/\n$//;
-		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { users_public_key => $users_public_key }});
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { users_public_key => $users_public_key }});
+		
+		# Now store the key in the 'host_key' table, if needed.
+		my $host_key_uuid = $anvil->Database->insert_or_update_host_keys({
+			debug               => 3,
+			host_key_host_uuid  => $anvil->Get->host_uuid, 
+			host_key_public_key => $users_public_key, 
+			host_key_user_name  => $user, 
+		});
+		
+		# Read in the existing 'known_hosts' file, if it exists. The 'old' and 'new' variables will 
+		# be used when looking for needed changes.
+		my $known_hosts_file_body = "";
+		my $known_hosts_old_body  = "";
+		my $known_hosts_new_body  = "";
+		my $known_hosts_file      = $ssh_directory."/known_hosts";
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { known_hosts_file => $known_hosts_file }});
+		if (-e $known_hosts_file)
+		{
+			$known_hosts_file_body = $anvil->Storage->read_file({file => $known_hosts_file});
+			$known_hosts_old_body  = $known_hosts_file_body;
+			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { known_hosts_file_body => $known_hosts_file_body }});
+		}
+		
+		# Read in the existing 'authorized_keys' file, if it exists.
+		my $authorized_keys_file_body = "";
+		my $authorized_keys_old_body  = "";
+		my $authorized_keys_new_body  = "";
+		my $authorized_keys_file      = $ssh_directory."/authorized_keys";
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { authorized_keys_file => $authorized_keys_file }});
+		if (-e $authorized_keys_file)
+		{
+			$authorized_keys_file_body = $anvil->Storage->read_file({file => $authorized_keys_file});
+			$authorized_keys_old_body  = $authorized_keys_file_body;
+			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { authorized_keys_file_body => $authorized_keys_file_body }});
+		}
+		
+		### Walk through each host we now know of. As we we do, loop through the old file body to see
+		### if it exists. If it does, and the key has changed, update the line with the new key. If
+		### it isn't found, add it. Once we check the old body for this entry, change the "old" body
+		### to the new one, then repeat the process.
+		
+		# Look at all the hosts I know about (other than myself) and see if any of the machine or 
+		# user keys either don't exist or have changed.
+		my $update_known_hosts     = 0;
+		my $update_authorized_keys = 0;
+		foreach my $host_uuid (keys %{$anvil->data->{peers}{ssh_keys}})
+		{
+			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { host_uuid => $host_uuid }});
+			foreach my $host_name (sort {$a cmp $b} keys %{$anvil->data->{peers}{ssh_keys}{$host_uuid}{host}})
+			{
+				my $key = $anvil->data->{peers}{ssh_keys}{$host_uuid}{host}{$host_name};
+				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+					's1:host_name' => $host_name,
+					's2:key'       => $key,
+				}});
+				
+				# Is this in the file and, if so, has it changed?
+				my $found     = 0;
+				my $test_line = $host_name." ".$key;
+				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { test_line => $test_line }});
+				foreach my $line (split/\n/, $known_hosts_old_body)
+				{
+					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { line => $line }});
+					if ($line eq $test_line)
+					{
+						# No change needed, key is the same.
+						$found = 1;
+						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { found => $found }});
+						last;
+					}
+					elsif ($line =~ /^$host_name /)
+					{
+						# Key has changed, update.
+						$found              = 1;
+						$line               = $test_line;
+						$update_known_hosts = 1;
+						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
+							found              => $found,
+							line               => $line, 
+							update_known_hosts => $update_known_hosts, 
+						}});
+					}
+					$known_hosts_new_body .= $line."\n";
+				}
+				# If we didn't find the key, add it.
+				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { found => $found }});
+				if (not $found)
+				{
+					$update_known_hosts   =  1;
+					$known_hosts_new_body .= $test_line."\n";
+					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
+						's1:update_known_hosts'   => $update_known_hosts, 
+						's2:known_hosts_new_body' => $known_hosts_new_body, 
+					}});
+				}
+				
+				# Move the new body over to the old body (even though it may not have 
+				# changed) and then clear the new body to prepare for the next pass.
+				$known_hosts_old_body = $known_hosts_new_body;
+				$known_hosts_new_body = "";
+			}
+		}
+		# Lastly, copy the last version of the old body to the new body,
+		$known_hosts_new_body = $known_hosts_old_body;
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
+			's1:update_known_hosts'    => $update_known_hosts, 
+			's2:known_hosts_file_body' => $known_hosts_file_body, 
+			's3:known_hosts_new_body'  => $known_hosts_new_body, 
+			's4:difference'            => diff \$known_hosts_file_body, \$known_hosts_new_body, { STYLE => 'Unified' },
+		}});
+		
+		die;
+		
+		# Update files, if needed.
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { update_known_hosts => $update_known_hosts }});
+		if ($update_known_hosts)
+		{
+			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, key => "log_0273", variables => { user => $user, file => $known_hosts_file }});
+			if (-e $known_hosts_file)
+			{
+				my $backup_file = $anvil->Storage->backup({
+					debug => 2,
+					fatal => 1, 
+					file  => $known_hosts_file, 
+				});
+				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { backup_file => $backup_file }});
+				if (-e $backup_file)
+				{
+					$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, key => "log_0154", variables => { source_file => $known_hosts_file, target_file => $backup_file }});
+				}
+				else
+				{
+					$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, priority => "alert", key => "error_0058", variables => { file => $known_hosts_file }});
+				}
+			}
+			my $failed = $anvil->Storage->write_file({
+				debug     => 3,
+				overwrite => 1, 
+				file      => $known_hosts_file, 
+				body      => $known_hosts_new_body, 
+				user      => $user, 
+				group     => $user, 
+				mode      => "0644", 
+			});
+			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { failed => $failed }});
+		}
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { update_authorized_keys => $update_authorized_keys }});
+		if ($update_authorized_keys)
+		{
+			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, key => "log_0273", variables => { user => $user, file => $authorized_keys_file }});
+			if (-e $authorized_keys_file)
+			{
+				my $backup_file = $anvil->Storage->backup({
+					debug => 2,
+					fatal => 1, 
+					file  => $authorized_keys_file, 
+				});
+				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { backup_file => $backup_file }});
+				if (-e $backup_file)
+				{
+					$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, key => "log_0154", variables => { source_file => $authorized_keys_file, target_file => $backup_file }});
+				}
+				else
+				{
+					$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, priority => "alert", key => "error_0058", variables => { file => $authorized_keys_file }});
+				}
+			}
+			my $failed = $anvil->Storage->write_file({
+				debug     => 3,
+				overwrite => 1, 
+				file      => $authorized_keys_file, 
+				body      => $authorized_keys_new_body, 
+				user      => $user, 
+				group     => $user, 
+				mode      => "0644", 
+			});
+			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { failed => $failed }});
+		}
+	}
+	
+	return(0);
+}
+
+# Get a list of machine host keys and user public keys from other machines.
+sub get_other_keys
+{
+	my ($anvil) = @_;
+	
+	delete $anvil->data->{peers}{ssh_keys};
+	
+	# Get the machine keys for other hosts.
+	my $query = "
+SELECT 
+   host_uuid, 
+   host_name, 
+   host_key 
+FROM 
+   hosts 
+WHERE 
+   host_uuid != ".$anvil->data->{sys}{database}{use_handle}->quote($anvil->Get->host_uuid)."
+;";
+	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { query => $query }});
+	
+	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
+	my $count   = @{$results};
+	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+		results => $results, 
+		count   => $count, 
+	}});
+	foreach my $row (@{$results})
+	{
+		my $host_uuid = $row->[0];
+		my $host_name = $row->[1];
+		my $host_key  = $row->[2];
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+			host_uuid => $host_uuid,
+			host_name => $host_name, 
+			host_key  => $host_key, 
+		}});
+		
+		$anvil->data->{peers}{ssh_keys}{$host_uuid}{host}{$host_name} = $host_key;
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+			"peers::ssh_keys::${host_uuid}::host::${host_name}" => $anvil->data->{peers}{ssh_keys}{$host_uuid}{host}{$host_name}, 
+		}});
+		
+		# If the host name is the long host name, create another entry with the short name.
+		if ($host_name =~ /^(.*?)\./)
+		{
+			my $short_hostname = $1;
+			$anvil->data->{peers}{ssh_keys}{$host_uuid}{host}{$short_hostname} = $host_key;
+			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+				"peers::ssh_keys::${host_uuid}::host::${short_hostname}" => $anvil->data->{peers}{ssh_keys}{$host_uuid}{host}{$short_hostname}, 
+			}});
+		}
+		
+		# Find any IP addresses for this host.
+		my $query = "SELECT ip_address_address FROM ip_addresses WHERE ip_address_host_uuid = ".$anvil->data->{sys}{database}{use_handle}->quote($host_uuid).";";
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { query => $query }});
+		
+		my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
+		my $count   = @{$results};
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+			results => $results, 
+			count   => $count, 
+		}});
+		foreach my $row (@{$results})
+		{
+			my $ip_address_address = $row->[0];
+			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+				ip_address_address => $ip_address_address,
+			}});
+			
+			$anvil->data->{peers}{ssh_keys}{$host_uuid}{host}{$ip_address_address} = $host_key;
+			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+				"peers::ssh_keys::${host_uuid}::host::${ip_address_address}" => $anvil->data->{peers}{ssh_keys}{$host_uuid}{host}{$ip_address_address}, 
+			}});
+		}
+		
+	}
+	
+	# Now read in the public key for other users on other machines.
+	$query = "
+SELECT 
+    host_key_host_uuid, 
+    host_key_user_name, 
+    host_key_public_key 
+FROM 
+    host_keys 
+WHERE 
+    host_key_host_uuid != ".$anvil->data->{sys}{database}{use_handle}->quote($anvil->Get->host_uuid)."
+;";
+	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { query => $query }});
+	
+	$results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
+	$count   = @{$results};
+	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+		results => $results, 
+		count   => $count, 
+	}});
+	foreach my $row (@{$results})
+	{
+		my $host_key_host_uuid  = $row->[0];
+		my $host_key_user_name  = $row->[1];
+		my $host_key_public_key = $row->[2];
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+			host_key_host_uuid  => $host_key_host_uuid,
+			host_key_user_name  => $host_key_user_name, 
+			host_key_public_key => $host_key_public_key, 
+		}});
+		
+		$anvil->data->{peers}{ssh_keys}{$host_key_host_uuid}{user}{$host_key_user_name} = $host_key_public_key;
+		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
+			"peers::ssh_keys::${host_key_host_uuid}::user::${host_key_user_name}" => $anvil->data->{peers}{ssh_keys}{$host_key_host_uuid}{user}{$host_key_user_name}, 
+		}});
 	}
 	
 	return(0);
@@ -489,7 +789,7 @@ FROM
 WHERE 
     variable_source_table = 'hosts' 
 AND 
-    variable_source_uuid = ".$anvil->data->{sys}{database}{use_handle}->quote($anvil->data->{sys}{host_uuid})." 
+    variable_source_uuid = ".$anvil->data->{sys}{database}{use_handle}->quote($anvil->Get->host_uuid)." 
 AND 
     variable_name = 'reboot::needed'
 ;";
diff --git a/tools/scancore b/tools/scancore
index 093b367f..06c06c42 100755
--- a/tools/scancore
+++ b/tools/scancore
@@ -220,7 +220,7 @@ sub exit_if_sums_changed
 	if ($anvil->Storage->check_md5sums)
 	{
 		# NOTE: We exit with '0' to prevent systemctl from showing a scary red message.
-		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 0, priority => "warn", key => "message_0014"});
+		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 0, priority => "alert", key => "message_0014"});
 		$anvil->nice_exit({code => 0});
 	}