diff --git a/lib/Ravada.pm b/lib/Ravada.pm
index 3b2898c66..ec51a0b96 100644
--- a/lib/Ravada.pm
+++ b/lib/Ravada.pm
@@ -1665,6 +1665,10 @@ sub _add_indexes_generic($self) {
             "index(id_domain)"
             ,"unique (id_bundle, id_domain)"
         ]
+        ,vm_which => [
+            "index(id_vm)"
+            ,"unique(id_vm,command,path)"
+        ]
     );
     my $if_not_exists = '';
     $if_not_exists = ' IF NOT EXISTS ' if $CONNECTOR->dbh->{Driver}{Name} =~ /sqlite|mariadb/i;
@@ -2457,6 +2461,14 @@ sub _sql_create_tables($self) {
                 ,date_changed => 'timestamp DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP'
             }
         ]
+        ,
+        [vm_which => {
+                id => 'integer PRIMARY KEY AUTO_INCREMENT',
+                ,id_vm => 'integer NOT NULL references `vms` (`id`) ON DELETE CASCADE',
+                ,command => 'char(40)'
+                ,path => 'varchar(255)'
+            }
+        ]
 
     );
     for my $new_table (@tables ) {
diff --git a/lib/Ravada/Domain.pm b/lib/Ravada/Domain.pm
index eb712a677..446521a0b 100644
--- a/lib/Ravada/Domain.pm
+++ b/lib/Ravada/Domain.pm
@@ -213,8 +213,7 @@ after 'screenshot' => \&_post_screenshot;
 
 after '_select_domain_db' => \&_post_select_domain_db;
 
-before 'migrate' => \&_pre_migrate;
-after 'migrate' => \&_post_migrate;
+around 'migrate' => \&_around_migrate;
 
 around 'get_info' => \&_around_get_info;
 around 'set_max_mem' => \&_around_set_max_mem;
@@ -329,7 +328,7 @@ sub _around_start($orig, $self, @arg) {
     $enable_host_devices = 1 if !defined $enable_host_devices;
     my $is_volatile = ($self->is_volatile || $arg{is_volatile});
 
-    for (1 .. 5) {
+    for (1 .. 2) {
         eval { $self->_start_checks(%arg, enable_host_devices => $enable_host_devices) };
         my $error = $@;
         if ($error) {
@@ -375,6 +374,8 @@ sub _around_start($orig, $self, @arg) {
         warn $error if $error;
         last if !$error;
 
+        $self->_dettach_host_devices() if $enable_host_devices && !$self->is_active();
+
         my $vm_name = Ravada::VM::_get_name_by_id($self->_data('id_vm'));
 
         die "Error: starting ".$self->name." on ".$vm_name." $error"
@@ -389,12 +390,10 @@ sub _around_start($orig, $self, @arg) {
         && $error !~ /Could not run .*swtpm/i
         && $error !~ /virtiofs/
         && $error !~ /child process/i
+        && $error !~ /host doesn.t support/
+        && $error !~ /device not found/
         ;
 
-        if ($error && $self->is_known && $self->id_base && !$self->is_local && $self->_vm->enabled) {
-            $self->_request_set_base();
-            next;
-        }
         die $error;
     }
     $self->_post_start(%arg);
@@ -579,16 +578,11 @@ sub _start_checks($self, @args) {
     my $id_base = $self->id_base;
     if ($id_base && !$is_volatile) {
         $self->_check_tmp_volumes();
-#        $self->_set_last_vm(1)
-        if ( !$self->is_local
-            && ( !$self->_vm->enabled || !base_in_vm($id_base,$self->_vm->id)
-                || !$self->_vm->ping) ) {
-            $self->_set_vm($vm_local, 1);
-        }
         if ( !$vm->is_alive ) {
             $vm->disconnect();
             $vm->connect;
             $vm = $vm_local if !$vm->is_local && !$vm->is_alive;
+            die "Error: node ".$vm->name." is not alive" if !$vm->is_alive;
         };
         if ($id_vm) {
             $self->_set_vm($vm);
@@ -1185,22 +1179,19 @@ sub _check_free_vm_memory {
 sub _check_tmp_volumes($self) {
     confess "Error: only clones temporary volumes can be checked."
         if !$self->id_base;
-    my $vm_local = $self->_vm->new( host => 'localhost' );
-    for my $vol ( $self->list_volumes_info) {
-        next unless $vol->file && $vol->file =~ /\.(TMP|SWAP)\./;
-        next if $vm_local->file_exists($vol->file);
-        $vol->delete();
+    my $vm = $self->_vm;
 
-        my $base = Ravada::Domain->open($self->id_base);
-        my @volumes = $base->list_files_base_target;
+    my $base = Ravada::Domain->open($self->id_base);
+    my @volumes = $base->list_files_base_target;
+    for my $vol ( $self->list_volumes_info) {
+        next unless $vol->file && $vol->file =~ /\.(TMP|SWAP)\.\w+$/;
         my ($file_base) = grep { $_->[1] eq $vol->info->{target} } @volumes;
-        if (!$file_base) {
-            warn "Error: I can't find base volume for target ".$vol->info->{target}
-                .Dumper(\@volumes);
-        }
+        next if !$file_base;
+
+        $vol->delete();
         my $vol_base = Ravada::Volume->new( file => $file_base->[0]
             , is_base => 1
-            , vm => $vm_local
+            , vm => $vm
         );
         $vol_base->clone(file => $vol->file);
     }
@@ -5337,6 +5328,14 @@ sub _post_migrate($self, $node, $request = undef) {
 
 }
 
+sub _around_migrate($orig, $self, $node, $request=undef) {
+    return if $self->_vm->id == $node->id;
+
+    $self->_pre_migrate($node, $request);
+    $self->$orig($node, $request);
+    $self->_post_migrate($node, $request);
+}
+
 sub _id_base_in_vm($self, $id_vm) {
     my $sth = $$CONNECTOR->dbh->prepare(
         "SELECT id FROM bases_vm "
diff --git a/lib/Ravada/Domain/KVM.pm b/lib/Ravada/Domain/KVM.pm
index 96fd9045e..80d5ba05b 100644
--- a/lib/Ravada/Domain/KVM.pm
+++ b/lib/Ravada/Domain/KVM.pm
@@ -694,7 +694,8 @@ sub post_resume_aux($self, %args) {
     # 55: domain is not running
     # 74: not configured
     # 86: no agent
-    die "$@\n" if $@ && $@ !~ /libvirt error code: (55|74|86),/;
+    # 84: qemu doesn't support rtc-reset-reinjection command
+    die "$@\n" if $@ && $@ !~ /libvirt error code: (55|74|84|86),/;
 }
 
 sub set_time($self) {
diff --git a/lib/Ravada/VM.pm b/lib/Ravada/VM.pm
index 65e02f158..44cea7ca4 100644
--- a/lib/Ravada/VM.pm
+++ b/lib/Ravada/VM.pm
@@ -318,6 +318,7 @@ sub BUILD {
     }
     $self->id;
 
+    $self->_which_cache_fetch();
 }
 
 sub _open_type {
@@ -552,15 +553,20 @@ sub _around_create_domain {
 
     return $base->_search_pool_clone($owner) if $from_pool;
 
-    if ($self->is_local && $base && $base->is_base && $args_create{volatile} && !$base->list_host_devices) {
+    if ($self->is_local && $base && $base->is_base && $args_create{volatile} && !$base->list_host_devices ) {
         $request->status("balancing")                       if $request;
         my $vm = $self->balance_vm($owner->id, $base);
 
         if (!$vm) {
             die "Error: No free nodes available.\n";
         }
+        if (!$vm->is_local) {
+            if ( $base->_base_files_in_vm($vm)
+                 && $base->_check_all_parents_in_node($vm)) {
+                $self = $vm;
+            }
+        }
         $request->status("creating machine on ".$vm->name)  if $request;
-        $self = $vm;
         $args_create{listen_ip} = $self->listen_ip($remote_ip);
     }
 
@@ -1405,8 +1411,9 @@ sub is_locked($self) {
         next if defined $at && $at < time + 2;
         next if !$args;
         my $args_d = decode_json($args);
-        if ( exists $args_d->{id_vm} && $args_d->{id_vm} == $self->id ) {
-            warn "locked by $command\n";
+        if ( exists $args_d->{id_vm}
+            && $args_d->{id_vm} =~ /^\d+$/
+            && $args_d->{id_vm} == $self->id ) {
             return 1;
         }
     }
@@ -1776,6 +1783,7 @@ sub _do_is_active($self, $force=undef) {
 }
 
 sub _cached_active($self, $value=undef) {
+    $self->_which_cache_flush() if defined $value && $value && !$self->_data('is_active');
     return $self->_data('is_active', $value);
 }
 
@@ -2740,8 +2748,50 @@ sub _list_qemu_bridges($self) {
     return keys %bridge;
 }
 
-sub _which($self, $command) {
+sub _which_cache_fetch($self) {
+    my $sth = $self->_dbh->prepare(
+        "SELECT command,path FROM vm_which "
+        ." WHERE id_vm=?"
+    );
+    $sth->execute($self->id);
+    while (my ($command, $path)) {
+        $self->{_which}->{$command} = $path;
+    }
+    $sth->finish;
+}
+
+
+sub _which_cache_get($self, $command) {
     return $self->{_which}->{$command} if exists $self->{_which} && exists $self->{_which}->{$command};
+}
+
+sub _which_cache_set($self, $command, $path) {
+    $self->{_which}->{$command} = $path;
+
+    eval {
+        my $sth = $self->_dbh->prepare(
+        "INSERT INTO vm_which (id_vm, command, path)"
+        ." VALUES (?,?,?) "
+        );
+        $sth->execute($self->id, $command, $path);
+    };
+    warn("Warning: $@ vm_which = ( ".$self->id.", $command, $path )")
+    if $@ && $@ !~ /Duplicate entry/i
+          && $@ !~ /UNIQUE constraint failed/i
+    ;
+}
+
+sub _which_cache_flush($self) {
+    my $sth = $self->_dbh->prepare(
+        "DELETE FROM vm_which where id_vm=?"
+    );
+    $sth->execute($self->id);
+}
+
+sub _which($self, $command) {
+
+    my $cached = $self->_which_cache_get($command);
+    return $cached if $cached;
 
     my $bin_which = $self->{_which}->{which};
     if (!$bin_which) {
@@ -2757,7 +2807,9 @@ sub _which($self, $command) {
     my @cmd = ( $bin_which,$command);
     my ($out,$err) = $self->run_command(@cmd);
     chomp $out;
-    $self->{_which}->{$command} = $out;
+
+    $self->_which_cache_set($command,$out);
+
     return $out;
 }
 
diff --git a/lib/Ravada/VM/KVM.pm b/lib/Ravada/VM/KVM.pm
index 919ed7dbb..df27f539a 100644
--- a/lib/Ravada/VM/KVM.pm
+++ b/lib/Ravada/VM/KVM.pm
@@ -615,6 +615,7 @@ sub file_exists($self, $file) {
 }
 
 sub _file_exists_remote($self, $file) {
+    return 1 if $self->search_volume($file);
     $file = $self->_follow_link($file) unless $file =~ /which$/;
     return if !$self->vm;
     for my $pool ($self->vm->list_all_storage_pools ) {
diff --git a/lib/Ravada/Volume.pm b/lib/Ravada/Volume.pm
index 9105ca61d..bc9fc44ad 100644
--- a/lib/Ravada/Volume.pm
+++ b/lib/Ravada/Volume.pm
@@ -95,7 +95,7 @@ sub _type_from_extension($file) {
 }
 
 sub _type($file,$vm = undef) {
-    return _type_from_file($file,$vm)   if $vm;
+    return _type_from_file($file,$vm)   if $vm && $vm->is_local;
     return (_type_from_extension($file) or 'QCOW2');
 }
 
diff --git a/lib/Ravada/Volume/QCOW2.pm b/lib/Ravada/Volume/QCOW2.pm
index a7a929120..9d718039c 100644
--- a/lib/Ravada/Volume/QCOW2.pm
+++ b/lib/Ravada/Volume/QCOW2.pm
@@ -17,7 +17,7 @@ has 'capacity' => (
     ,builder => '_get_capacity'
 );
 
-our $QEMU_IMG = "/usr/bin/qemu-img";
+our $QEMU_IMG = "qemu-img";
 
 sub prepare_base($self) {
 
diff --git a/t/device/40_mediated_device.t b/t/device/40_mediated_device.t
index 39c16370a..887d83f7a 100644
--- a/t/device/40_mediated_device.t
+++ b/t/device/40_mediated_device.t
@@ -447,6 +447,9 @@ sub test_mdev_kvm_state($vm) {
     test_old_in_locked($domain);
     test_timer($domain,'present' => 'yes');
 
+    # TODO:
+    # test_locked_hd($domain);
+
     _req_shutdown($domain);
     $domain->_dettach_host_devices();
 
@@ -459,6 +462,20 @@ sub test_mdev_kvm_state($vm) {
 
 }
 
+sub test_locked_hd($domain) {
+    my $sth = connector->dbh->prepare("DELETE FROM host_devices_domain_locked WHERE id_domain=?");
+        $sth->execute($domain->id);
+
+    my @domain_hds = $domain->list_host_devices_attached();
+    Ravada::Request->refresh_machine(
+        uid => user_admin->id
+        ,id_domain => $domain->id
+    );
+    wait_request();
+    @domain_hds = $domain->list_host_devices_attached();
+    is($domain_hds[0]->{is_locked},1);
+}
+
 sub test_old_in_locked($domain) {
     my $sth = connector->dbh->prepare("SELECT config_no_hd FROM domains d "
         ." WHERE id=?"
@@ -883,6 +900,28 @@ sub test_volatile_clones($vm, $domain, $host_device) {
     is($host_device->list_available_devices(), $max_n_device) or exit;
 }
 
+sub test_start_failed($vm) {
+    return if $vm->type eq 'Void'; # Void HDs will not fail
+    my $hd = _create_mdev($vm);
+
+    my $dir = _prepare_dir_mdev();
+    $hd->_data('list_command' => "ls $dir");
+
+    my $domain = create_domain($vm);
+    $domain->add_host_device($hd->id);
+
+    my $req = Ravada::Request->start_domain(uid => user_admin->id
+        ,id_domain => $domain->id
+    );
+    wait_request( check_error => 0);
+
+    test_xml_no_hd($domain);
+
+    remove_domain($domain);
+    $hd->remove();
+}
+
+
 ####################################################################
 
 clean();
diff --git a/t/mojo/30_settings.t b/t/mojo/30_settings.t
index 21c399ca8..eb86d5bd5 100644
--- a/t/mojo/30_settings.t
+++ b/t/mojo/30_settings.t
@@ -27,7 +27,7 @@ my %FILES;
 my %HREFS;
 
 my %MISSING_LANG = map {$_ => 1 }
-    qw(ca-valencia he ko);
+    qw(ca-valencia cs he ko);
 
 my $ID_DOMAIN;
 
@@ -503,7 +503,7 @@ sub test_languages() {
     while (my $file = readdir $ls) {
         next if $file !~ /(.*)\.po$/;
         next if $MISSING_LANG{$1};
-        ok($lang->{$1},"Expecting $1 in select");
+        ok($lang->{$1},"Expecting $1 in language select");
     }
 }