diff --git a/apt/APT_Instance.pm.in b/apt/APT_Instance.pm.in
index 5d7a2eeff078230d6da72b3365b4a8174fc349b4..a43e87bbd379594fea8cad41a78f6152711769e9 100644
--- a/apt/APT_Instance.pm.in
+++ b/apt/APT_Instance.pm.in
@@ -406,6 +406,42 @@ sub SetManifest($$)
     return 0;
 }
 
+sub MarkCanceled($)
+{
+    my ($self) = @_;
+
+    # Must be a real reference. 
+    return -1
+	if (! ref($self));
+
+    my $uuid = $self->uuid();
+
+    DBQueryWarn("update apt_instances set ".
+		"  canceled=1,canceled_timestamp=now() ".
+		"where uuid='$uuid'")
+	or return -1;
+
+    $self->{'INSTANCE'}->{'canceled'} = 1;
+    return 0;
+}
+# We need to bypass the in memory state for this.
+sub IsCanceled($)
+{
+    my ($self) = @_;
+    my $uuid = $self->uuid();
+
+    my $query_result =
+	DBQueryWarn("select canceled from apt_instances ".
+		    "where uuid='$uuid'");
+	
+    return -1
+	if (!$query_result);
+    return 0
+	if (!$query_result->numrows);
+    my ($canceled) = $query_result->fetchrow_array();
+    return $canceled;
+}
+
 #
 # Set to use the logfile. 
 #
@@ -1205,7 +1241,9 @@ sub Terminate($)
 			    $speaksfor_credential->asString()];
 	}
 	$method = "DeleteSliver";
-	@params = ($slice->urn(), $credentials, {"blocking" => 'true'});
+	@params = ($slice->urn(), $credentials,
+		   {"blocking" => 'true',
+		    "cancel"   => 'true'});
 	
 	# Convert URL to use AM interface.
 	$cmurl =~ s/\/cm$/\/am/;
diff --git a/apt/create_instance.in b/apt/create_instance.in
index 14864fc2e86f51fea384e78299ea680a05c6550f..bae618fdaf0de8b9ced7ad87416ceb7209495a37 100755
--- a/apt/create_instance.in
+++ b/apt/create_instance.in
@@ -847,6 +847,7 @@ sub WaitForSliver($)
     my $interval = 15;
     my $ready    = 0;
     my $failed   = 0;
+    my $rpcfail  = 0;
     my $public_url;
     my $repblob;
     my $laststatus;
@@ -859,7 +860,8 @@ sub WaitForSliver($)
 	if (!defined($response) || !defined($response->value()) ||
 	    ($response->code() != GENIRESPONSE_SUCCESS &&
 	     $response->code() != GENIRESPONSE_SERVER_UNAVAILABLE &&
-	     $response->code() != GENIRESPONSE_BUSY)) {
+	     $response->code() != GENIRESPONSE_BUSY &&
+	     $response->code() != GENIRESPONSE_RPCERROR)) {
 	    print STDERR "SliverStatus failed";
 	    
 	    if (defined($response)) {
@@ -878,6 +880,23 @@ sub WaitForSliver($)
 	    $failed = 1;
 	    last;
 	}
+	if ($response->code() == GENIRESPONSE_RPCERROR) {
+	    if ($rpcfail > 10) {
+		if ($response->output() =~ /read timeout/) {
+		    $webtask->output("Lost contact with the aggregate. " .
+				     "Possibly a network failure, ".
+				     "please try again later.");
+		}
+		else {
+		    $webtask->output($response->output());
+		}
+		$failed = 1;
+		last;
+	    }
+	    $rpcfail++;
+	    next;
+	}
+	$rpcfail = 0;
 	next
 	    if ($response->code() == GENIRESPONSE_BUSY ||
 		$response->code() == GENIRESPONSE_SERVER_UNAVAILABLE);
@@ -888,6 +907,7 @@ sub WaitForSliver($)
 	# cares about. We get this on each loop, update so the web
 	# interface can show changes.
 	#
+	my $changed = 0;
 	my $statusblob = {};
 	foreach my $urn (keys(%{$repblob->{'details'}})) {
 	    my $details = $repblob->{'details'}->{$urn};
@@ -940,6 +960,13 @@ sub WaitForSliver($)
 	    $webtask->output("Experiment setup on $urn failed");
 	    last;
 	}
+	elsif ($instance->IsCanceled()) {
+	    last;
+	}
+    }
+    if ($instance->IsCanceled()) {
+	$webtask->Exited(0);
+	return 0;
     }
     if ($failed || !$ready) {
 	$aggobj->SetStatus("failed");
@@ -981,6 +1008,18 @@ print "$slice_urn\n";
 # Count up nodes running a startup service.
 my $startuprunning = 0;
 
+#
+# If we were canceled, then none of the stuff below matters, we
+# are going to do a terminate.
+#
+if ($instance->IsCanceled()) {
+    $instance->SetStatus("canceled");
+    $slice->UnLock();
+
+    system("$MANAGEINSTANCE -t $webtask_id terminate $quickvm_uuid");
+    exit(0);
+}
+
 #
 # Check the exit codes; any failure is a total failure (for now).
 #
diff --git a/apt/manage_instance.in b/apt/manage_instance.in
index 5c6bb2b10bf65ea47a010f2d9374b03544442b02..53d9a4d52ef3b14fb20a8cd6709bf78a23012333 100644
--- a/apt/manage_instance.in
+++ b/apt/manage_instance.in
@@ -1015,7 +1015,22 @@ sub DoTerminate()
     # a disk image.
     #
     if ($slice->Lock()) {
-	fatal("Slice is busy, cannot lock it");
+	#
+	# A special case is if the slice is provisioning. This means the
+	# user is giving up on it, and we want to tell the aggregate to
+	# kill it. Not all aggregates are going to allow this, so need
+	# to be able to deal with that.
+	#
+	if ($instance->status() ne "provisioned") {
+	    fatal("Slice is busy, cannot lock it");
+	}
+	if (!$instance->canceled()) {
+	    print "Marking instance canceled\n";
+	    $instance->MarkCanceled();
+	}
+	sleep(1);
+	# We have an obvious race here since we do not have the lock.
+	exit(0);
     }
     my $old_status = $instance->status();
     $instance->SetStatus("terminating");
diff --git a/www/aptui/instance_defs.php b/www/aptui/instance_defs.php
index 69adb8508c64391ebee74dc5b27aa53eb0981d44..795cdffeef49278102f918e2e6cad7f3fa6dac1a 100644
--- a/www/aptui/instance_defs.php
+++ b/www/aptui/instance_defs.php
@@ -134,6 +134,7 @@ class Instance
     function profile_id()   { return $this->field('profile_id'); }
     function profile_version() { return $this->field('profile_version'); }
     function status()	    { return $this->field('status'); }
+    function canceled()	    { return $this->field('canceled'); }
     function pid()	    { return $this->field('pid'); }
     function pid_idx()	    { return $this->field('pid_idx'); }
     function public_url()   { return $this->field('public_url'); }
diff --git a/www/aptui/js/status.js b/www/aptui/js/status.js
index f0b11316ccff5e3c433477d29d1ef78800f71db1..49e4be4a9cc789843f177be3cbff25c66143c8ad 100644
--- a/www/aptui/js/status.js
+++ b/www/aptui/js/status.js
@@ -379,6 +379,13 @@ function (_, sup, moment, marked, UriTemplate, ShowImagingModal,
 	    else if (status == 'provisioned') {
 		$("#status_progress_bar").width("66%");
 		status_html = "booting";
+		if (json.value.canceled) {
+		    status_html += " (but canceled)";
+		}
+		else {
+		    // So the user can cancel. 
+		    EnableButton("terminate");
+		}
 	    }
 	    else if (status == 'ready') {
 		bgtype = "panel-success";
@@ -397,6 +404,7 @@ function (_, sup, moment, marked, UriTemplate, ShowImagingModal,
 		    $("#status_progress_div").addClass("progress-bar-success");
 		    $("#status_progress_bar").width("100%");
 		}
+		$('#error_panel').addClass("hidden");
 		EnableButtons();
 		// We should be looking at the node status instead.
 		if (lastStatus != "imaging") {
diff --git a/www/aptui/myexperiments.php b/www/aptui/myexperiments.php
index e8daa582ac0b8761b34a7b5bb7391b74cd11f5cd..776c62679b2563ff540e697604aacc3614ba02f2 100644
--- a/www/aptui/myexperiments.php
+++ b/www/aptui/myexperiments.php
@@ -180,6 +180,7 @@ function SPITROWS($showall, $name, $result)
         $uuid         = $row["uuid"];
         $name         = $row["name"];
         $status       = $row["status"];
+        $canceled     = $row["canceled"];
         $created      = DateStringGMT($row["created"]);
         $expires      = DateStringGMT($row["expires"]);
         $creator_idx  = $row["creator_idx"];
@@ -206,6 +207,9 @@ function SPITROWS($showall, $name, $result)
         if ($row["expired"]) {
             $status = "expired";
         }
+        elseif ($canceled) {
+            $status = "canceled";
+        }
         $profile = Profile::Lookup($profile_id, $version);
         if ($profile) {
             $profile_name  = $profile->name();
diff --git a/www/aptui/status.ajax b/www/aptui/status.ajax
index 5035f54dd0b1f937fe6b3ec1e4744c21b3545d99..e7da73d1de8bdf16cfe80e0839495dd0a09131fa 100644
--- a/www/aptui/status.ajax
+++ b/www/aptui/status.ajax
@@ -120,6 +120,7 @@ function Do_GetInstanceStatus()
     }
     $blob = array();
     $blob["status"] = $instance->status();
+    $blob["canceled"] = $instance->canceled() ? 1 : 0;
     $blob["sliverstatus"] = array();
     $blob["sliverurls"]   = array();