diff --git a/Notes b/Notes
index 316bb30..206dd9f 100644
--- a/Notes
+++ b/Notes
@@ -63,3 +63,9 @@ Tape performance:
 
 Equality checking doesn't work for setuid files.
 
+Implement equality checking via saved checksum.
+
+checksum is null if file is linked. Is that ok? Can this be solved
+together with the previous point?
+
+exit if disk full
diff --git a/lib/Simba/CA.pm b/lib/Simba/CA.pm
index ff967d2..d3809b4 100644
--- a/lib/Simba/CA.pm
+++ b/lib/Simba/CA.pm
@@ -119,7 +119,8 @@ sub backup2disk {
                 my $header = <$file_dfd>; # this should be the same as $_ - check?
                 if ($header =~ /^data (.*)/) {
                     my $f2 = $self->parse($1);
-                    open(my $file_bfd, '>:raw', "$self->{this_backup}/$f->{name}") or die; # XXX
+                    my $backup_filename = "$self->{this_backup}/$f->{name}";
+                    open(my $file_bfd, '>:raw', $backup_filename) or die "cannot open backup file $backup_filename: $!";
                     my $size = $f2->{s};
                     my $err;
                     my $sha1 = Digest::SHA1->new;
@@ -136,11 +137,11 @@ sub backup2disk {
                             $self->log(5, "unexpected EOF reading from data socket");
                             last;
                         }
-                        $file_bfd->print($buffer);
+                        $file_bfd->print($buffer) or die "write to backup failed: $!";
                         $size -= length($buffer);
                         $sha1->add($buffer);
                     }
-                    close($file_bfd);
+                    close($file_bfd) or die "write to backup failed: $!";
                     my $trailer = <$file_dfd>; # should be empty line
                     $trailer = <$file_dfd>; 
                     if ($trailer =~ /^fail /) {
@@ -347,7 +348,8 @@ sub name2gid {
 sub log {
     my ($self, $level, $msg) = @_;
     if ($level <= $self->{log_level}) {
-        $self->{fh_log}->print(strftime("%Y-%m-%dT%H:%M:%S%z", localtime), " $$ [$level]: $msg\n");
+        $self->{fh_log}->print(strftime("%Y-%m-%dT%H:%M:%S%z", localtime), " $$ [$level]: $msg\n") 
+            or die "write to log failed: $!";
     }
 }
 
@@ -377,7 +379,8 @@ sub db_record_version {
                                            file_owner, file_group, file_acl,
                                            file_unix_bits,
                                            file_rdev,
-                                           date, checksum, online, file_linktarget)
+                                           date, checksum, online, file_linktarget,
+                                           session)
                       values(?,
                              ?, ?, ?, ?,
                              ?, ?, ?,
@@ -398,7 +401,7 @@ sub db_record_version {
 
 sub new_session {
     my ($self) = @_;
-    $self->{dbh}->do("insert into sessions(start_date, prefix)", {}, time(), $self->{this_backup});
+    $self->{dbh}->do("insert into sessions(start_date, prefix) values(?, ?)", {}, time(), $self->{this_backup});
     $self->{session_id} = $self->{dbh}->{'mysql_insertid'};
 }
 
diff --git a/lib/Simba/DA.pm b/lib/Simba/DA.pm
index 04efe2e..e31cf49 100644
--- a/lib/Simba/DA.pm
+++ b/lib/Simba/DA.pm
@@ -284,7 +284,8 @@ sub no_such_command {
 sub log {
     my ($self, $level, $msg) = @_;
     if ($level <= $self->{log_level}) {
-        $self->{fh_log}->print(strftime("%Y-%m-%dT%H:%M:%S%z", localtime), " $$ [$level]: $msg\n");
+        $self->{fh_log}->print(strftime("%Y-%m-%dT%H:%M:%S%z", localtime), " $$ [$level]: $msg\n")
+            or die "write to log failed: $!";
     }
 }