diff --git a/Makefile b/Makefile
index a519794..0a1f301 100644
--- a/Makefile
+++ b/Makefile
@@ -122,7 +122,7 @@ run-gdb: all
 	-ex "set args -C debian/etc -M debian/var/models -U debian/var/users"
 
 run-valgrind: all
-	@valgrind --leak-check=full -s  \
+	@valgrind --leak-check=full --show-leak-kinds=all -s  \
 	bin/gem-graph-server -C debian/etc -M debian/var/models \
 	-U debian/var/users
 
diff --git a/include/base.h b/include/base.h
index 0b82901..ed2dc5f 100644
--- a/include/base.h
+++ b/include/base.h
@@ -37,7 +37,7 @@
 #define LOGMSG "[%s]"
 #define printLog(FORMAT, ...) printf("\e[0m" LOGMSG " " FORMAT "\e[0m", \
                                                  __func__, ##__VA_ARGS__)
-#define printErr(FORMAT,...) sprintf(stderr, "\e[0m" LOGMSG " " FORMAT "\e[0m",\
+#define printErr(FORMAT,...) fprintf(stderr, "\e[0m" LOGMSG " " FORMAT "\e[0m",\
                                                  __func__, ##__VA_ARGS__)
 #define LEN(x)  (sizeof(x) / sizeof((x)[0]))
 
diff --git a/include/terminal.h b/include/terminal.h
index 7c1f68d..1a5107e 100644
--- a/include/terminal.h
+++ b/include/terminal.h
@@ -74,7 +74,7 @@ static inline int TermGetch(bool nonBlocking)
         fcntl(0, F_SETFL, O_NONBLOCK);
 
     if(tcgetattr(0, &old) < 0) {
-        printLog("%sError getting terminal settings! (%s)\n",
+        printErr("%sError getting terminal settings! (%s)\n",
                  C_COLOR_RED,
                  strerror(errno));
         return -1;
@@ -84,7 +84,7 @@ static inline int TermGetch(bool nonBlocking)
     old.c_lflag &= ~ECHO;   // set no echo mode
 
     if(tcsetattr(0, TCSANOW, &old) < 0) {
-        printLog("%sError setting terminal settings! (%s)\n",
+        printErr("%sError setting terminal settings! (%s)\n",
                  C_COLOR_RED,
                  strerror(errno));
         return -1;
@@ -96,7 +96,7 @@ static inline int TermGetch(bool nonBlocking)
         if(errno == EAGAIN)
             return 0;
 
-        printLog("%sError reading character! (%s)\n",
+        printErr("%sError reading character! (%s)\n",
                  C_COLOR_RED,
                  strerror(errno));
         return -1;
@@ -106,7 +106,7 @@ static inline int TermGetch(bool nonBlocking)
     old.c_lflag |= ECHO;   // set echo mode
 
     if(tcsetattr(0, TCSADRAIN, &old) < 0) {
-        printLog("%sError resetting terminal settings! (%s)\n",
+        printErr("%sError resetting terminal settings! (%s)\n",
                  C_COLOR_RED,
                  strerror(errno));
         return -1;
diff --git a/src/cli.c b/src/cli.c
index b298b28..1631b3d 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -444,7 +444,7 @@ int main(void)
     // Socket creation
     sockfd = socket(AF_INET, SOCK_STREAM, 0);
     if (sockfd == -1) {
-        printLog("%sSocket creation failed! (%s)\n",
+        printErr("%sSocket creation failed! (%s)\n",
                  C_COLOR_RED,
                  strerror(errno));
         return 1;
@@ -459,7 +459,7 @@ int main(void)
 
     // Connect to the server
     if (connect(sockfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) != 0) {
-        printLog("%sConnection failed! (%s)\n",
+        printErr("%sConnection failed! (%s)\n",
                  C_COLOR_RED,
                  strerror(errno));
         return 2;
diff --git a/src/cmds.c b/src/cmds.c
index e6557c2..9de3fd4 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -34,7 +34,8 @@ char *CmdModel(char *buf, char **argv, Server_t *args)
 
     // invalid use
     if (!argv[1]) {
-        strcat(buf, "{create | delete | load | run | stop | list | info}\n");
+        strcat(buf, "{create | delete | load | unload | run | stop | list |"
+            "info}\n");
         goto CmdModelEnd;
     }
 
@@ -100,6 +101,28 @@ char *CmdModel(char *buf, char **argv, Server_t *args)
         goto CmdModelEnd;
     }
 
+    else if (strcmp(argv[1], "unload") == 0) {
+        if (!argv[2]) {
+            goto unloadEnd;
+        }
+
+        id = (int) strtol(argv[2] + 3, NULL, 10);
+
+        if (id == 0 || ModelUnload(id) < 0) {
+            printErr("Failed to unload model id %d\n", id);
+            sprintf(buf + strlen(buf), "Failed to unload model id %d\n", id);
+            goto CmdModelEnd;
+        }
+
+        sprintf(buf + strlen(buf), "Model id %d unloaded\n", id);
+        goto CmdModelEnd;
+        unloadEnd:
+        // invalid use
+        strcat(buf, "Unloads a model structure\n");
+        strcat(buf, "Usage: model unload id=ID\n");
+        goto CmdModelEnd;
+    }
+
     else if (strcmp(argv[1], "delete") == 0) {
         if (!argv[2]) {
             goto deleteEnd;
@@ -172,7 +195,8 @@ char *CmdModel(char *buf, char **argv, Server_t *args)
     }
 
     // invalid use
-    else strcat(buf, "{create | delete | load | run | stop | list | info}\n");
+    else strcat(buf, "{create | delete | load | unload | run | stop | list |"
+        "info}\n");
 
 CmdModelEnd:
     return buf;
diff --git a/src/main.c b/src/main.c
index 6dd30b4..a7e9667 100644
--- a/src/main.c
+++ b/src/main.c
@@ -59,12 +59,12 @@ int main(int argc, char **argv)
             strcpy(parameters.modelDir, optarg);
             break;
         case 'U':
-            printLog("User : %s\n", optarg);
+            printLog("Users : %s\n", optarg);
             parameters.userDir = (char*) calloc(1, strlen(optarg) + 1);
             strcpy(parameters.userDir, optarg);
             break;
         case ':':
-            printLog("Option missing argument : %c\n", optopt);
+            printErr("Option missing argument : %c\n", optopt);
             if (parameters.configDir)
                 free(parameters.configDir);
 
@@ -77,7 +77,7 @@ int main(int argc, char **argv)
             return ENOSYS;
             break;
         case '?':
-            printLog("Unknown option : %c\n", optopt);
+            printErr("Unknown option : %c\n", optopt);
             if (parameters.configDir)
                 free(parameters.configDir);
 
@@ -93,7 +93,7 @@ int main(int argc, char **argv)
     }
 
     if (!parameters.configDir | !parameters.modelDir | !parameters.userDir) {
-        printLog("Missing arguments\n");
+        printErr("Missing arguments\n");
 
         if (parameters.configDir)
             free(parameters.configDir);
diff --git a/src/model.c b/src/model.c
index b214baa..21491e0 100644
--- a/src/model.c
+++ b/src/model.c
@@ -64,6 +64,7 @@ int ModelLoad(int id)
 
     printLog("Loading model id %d (/%d models)...\n", id, knownModelSize);
 
+
     // Creating structure for the Scheduler
     knownModel[id-1]->scheduler = (Scheduler_t*) calloc(1, sizeof(Scheduler_t));
 
@@ -79,12 +80,20 @@ int ModelLoad(int id)
 int ModelUnload(int id)
 {
     // Destroy scheduler
-    SchedDestroy(loadedModel[id-1]->scheduler);
-    loadedModel[id-1]->scheduler = NULL;
+    if (id > loadedModelSize)
+        return -1;
 
+    if (loadedModel[id-1]->scheduler) {
+        SchedDestroy(loadedModel[id-1]->scheduler);
+        loadedModel[id-1]->scheduler = NULL;
+    }
+
+    // Prevent fragmentation by moving data in the newly freed slot
+    if (id-1 < loadedModelSize) {
     memmove(&loadedModel[id-1],
             &loadedModel[id-1] + sizeof(Model_t*),
             loadedModelSize - (id-1));
+    }
 
     // Decrement loaded model index
     loadedModelSize--;
@@ -243,7 +252,7 @@ void ModelSystemInit(Parameters_t *parameters)
 
     // Open model directory
     if ((modelDir = opendir(parameters->modelDir)) <= 0) {
-        printLog("Could not open %s\n", parameters->modelDir);
+        printErr("Could not open %s\n", parameters->modelDir);
         ModelSystemDestroy();
         kill(getpid(), SIGTERM);
         return;
@@ -275,7 +284,7 @@ void ModelSystemInit(Parameters_t *parameters)
 
             // Ask to parse the new model
             if (ParseModelIdentityXML(newModel, parameters) != 0) {
-                printLog("Deleting invalid model %s from known list\n",
+                printErr("Deleting invalid model %s from known list\n",
                          newModel->name);
                 ModelDelete(newModel->id);
                 continue;
@@ -283,7 +292,7 @@ void ModelSystemInit(Parameters_t *parameters)
 
             // Check model is valid and/or parsed
             if (newModel->validated == false) {
-                printLog("Deleting invalid model %s from known list\n",
+                printErr("Deleting invalid model %s from known list\n",
                          newModel->name);
                 ModelDelete(newModel->id);
                 continue;
diff --git a/src/parsing.c b/src/parsing.c
index c1336ef..edcecb5 100644
--- a/src/parsing.c
+++ b/src/parsing.c
@@ -336,7 +336,7 @@ int ParseModelIdentityXML(Model_t *model, Parameters_t *params)
     xmlDocument = xmlParseFile(model->filename);
 
     if (xmlDocument == NULL) {
-        printLog("Can't parse model file at '%s'.\n", model->filename);
+        printErr("Can't parse model file at '%s'.\n", model->filename);
         return -1;
     }
 
@@ -344,7 +344,7 @@ int ParseModelIdentityXML(Model_t *model, Parameters_t *params)
     currentNode = xmlDocGetRootElement(xmlDocument);
 
     if (currentNode == NULL) {
-        printLog("Invalid model file at '%s', document empty !\n",
+        printErr("Invalid model file at '%s', document empty !\n",
                  model->filename);
         xmlFreeDoc(xmlDocument);
         free(schemPath);
@@ -353,7 +353,7 @@ int ParseModelIdentityXML(Model_t *model, Parameters_t *params)
 
     // Checking that XML file is actually a model
     if (xmlStrcmp(currentNode->name, (const xmlChar *) "gem-graph-model")) {
-        printLog("Invalid model file at '%s', "
+        printErr("Invalid model file at '%s', "
                  "root node is not <gem-graph-model> !\n",
                  model->filename);
         xmlFreeDoc(xmlDocument);
@@ -365,12 +365,12 @@ int ParseModelIdentityXML(Model_t *model, Parameters_t *params)
     version = xmlGetProp(currentNode, (xmlChar*)"version");
     // Check version is present
     if (!version) {
-        printLog("Missing version for model %s \n", model->name);
+        printErr("Missing version for model %s \n", model->name);
         xmlFreeDoc(xmlDocument);
         free(schemPath);
         return -4;
     } else if (strlen((char*)version) > MODEL_STRING_SIZE) {
-        printLog("Invalid version number for model %s \n", model->name);
+        printErr("Invalid version number for model %s \n", model->name);
         free(version);
         xmlFreeDoc(xmlDocument);
         free(schemPath);
@@ -384,7 +384,7 @@ int ParseModelIdentityXML(Model_t *model, Parameters_t *params)
     // Loading schema file
     schemFile = xmlSchemaNewParserCtxt(schemPath);
     if (schemFile == NULL) {
-        printLog("Invalid gem-graph version %s in model %s: no schema present",
+        printErr("Invalid gem-graph version %s in model %s: no schema present",
                  version, model->name);
         free(version);
         xmlFreeDoc(xmlDocument);
@@ -394,9 +394,9 @@ int ParseModelIdentityXML(Model_t *model, Parameters_t *params)
 
     // Loading schema file content
     schemPtr = xmlSchemaParse(schemFile);
-    xmlSchemaFreeParserCtxt(schemFile);
     if (schemPtr == NULL) {
-        printLog("Invalid schema file, version %s\n", version);
+        printErr("Invalid schema file, version %s\n", version);
+        xmlSchemaFreeParserCtxt(schemFile);
         free(version);
         xmlFreeDoc(xmlDocument);
         free(schemPath);
@@ -406,11 +406,12 @@ int ParseModelIdentityXML(Model_t *model, Parameters_t *params)
     // Creating validating context
     schemValidator = xmlSchemaNewValidCtxt(schemPtr);
     if (schemValidator == NULL) {
+        xmlSchemaFreeParserCtxt(schemFile);
         xmlSchemaFree(schemPtr);
         free(version);
         xmlFreeDoc(xmlDocument);
         free(schemPath);
-        printLog("An error occured preparing schema file, version %s\n", version);
+        printErr("An error occured preparing schema file, version %s\n", version);
         return -7;
     }
 
@@ -441,6 +442,7 @@ int ParseModelIdentityXML(Model_t *model, Parameters_t *params)
     currentNode = currentNode->next;
     }
 
+    xmlSchemaFreeParserCtxt(schemFile);
     xmlSchemaFreeValidCtxt(schemValidator);
     xmlSchemaFree(schemPtr);
     free(version);
@@ -514,21 +516,21 @@ int ParseModelXML(Model_t *model)
     xmlDocument = xmlParseFile(model->filename);
 
     if (xmlDocument == NULL) {
-        printLog("Can't parse model file at '%s'.\n", model->filename);
+        printErr("Can't parse model file at '%s'.\n", model->filename);
         return -1;
     }
 
     currentNode = xmlDocGetRootElement(xmlDocument);
 
     if (currentNode == NULL) {
-        printLog("Invalid model file at '%s', document empty !\n",
+        printErr("Invalid model file at '%s', document empty !\n",
                  model->filename);
         xmlFreeDoc(xmlDocument);
         return -2;
     }
 
     if (xmlStrcmp(currentNode->name, (const xmlChar *) "gem-graph-model")) {
-        printLog("Invalid model file at '%s', "
+        printErr("Invalid model file at '%s', "
                  "root node is not <gem-graph-model> !\n",
                  model->filename);
         xmlFreeDoc(xmlDocument);
diff --git a/src/scheduler.c b/src/scheduler.c
index c159bf4..82a9268 100644
--- a/src/scheduler.c
+++ b/src/scheduler.c
@@ -105,8 +105,8 @@ static void *schedulerMain(void *scheduler)
     centersList = (Center_t*) calloc(1, sizeof(Center_t));
 
     // Initiate the arrowArray lock
-    if (err = ArrowsInitLock(args->arrowArray), err != 0) { // TODO destroy this
-        printLog("Impossible to create the arrow array lock (error %d)\n", err);
+    if (err = ArrowsInitLock(args->arrowArray), err != 0) {
+        printErr("Impossible to create the arrow array lock (error %d)\n", err);
         return NULL;
     }
     //
@@ -215,6 +215,9 @@ static void *schedulerMain(void *scheduler)
 
     printLog("Scheduler #%lu offline\n", args->id);
 
+
+    ArrowsDestroyLock(args->arrowArray);
+
     free(workerArray);
     workerArray = NULL;
     free(centersList);
diff --git a/src/server.c b/src/server.c
index f9986b4..400012e 100644
--- a/src/server.c
+++ b/src/server.c
@@ -75,7 +75,7 @@ void *serverCommunicationInstance(void *server)
         // Read the message from client and copy it in buffer
         bytesReceived = recv(args->sockfd, receiveBuff, RECEIVE_BUFFER_SIZE, 0);
         if (bytesReceived == -1) {
-            printLog("Could not receive data! (%s)\n", strerror(errno));
+            printErr("Could not receive data! (%s)\n", strerror(errno));
             break;
         };
 
@@ -148,7 +148,7 @@ static void *serverMain(void *server)
     // Create socket
     args->sockfd = socket(AF_INET, SOCK_STREAM, 0);
     if (args->sockfd == -1) {
-        printLog("Socket creation failed! (%s)\n", strerror(errno));
+        printErr("Socket creation failed! (%s)\n", strerror(errno));
         args->returnValue = 1;
         goto serverExiting;
     }
@@ -156,14 +156,14 @@ static void *serverMain(void *server)
     // Get socket flags
     flags = fcntl(args->sockfd, F_GETFL);
     if (flags == -1) {
-        printLog("Socket parameters getting failed! (%s)\n", strerror(errno));
+        printErr("Socket parameters getting failed! (%s)\n", strerror(errno));
         args->returnValue = 1;
         goto serverExiting;
     }
 
     // Change socket flags to non-blocking
     if (fcntl(args->sockfd, F_SETFL, flags | O_NONBLOCK) < 0) {
-        printLog("Socket non-blocking setting failed! (%s)\n", strerror(errno));
+        printErr("Socket non-blocking setting failed! (%s)\n", strerror(errno));
         args->returnValue = 1;
         goto serverExiting;
     }
@@ -179,14 +179,14 @@ static void *serverMain(void *server)
     // Binding newly created socket
     if ((bind(args->sockfd, (struct sockaddr*)&servaddr,
               sizeof(servaddr))) == -1) {
-        printLog("Socket bind failed! (%s)\n", strerror(errno));
+        printErr("Socket bind failed! (%s)\n", strerror(errno));
         args->returnValue = 1;
         goto serverExiting;
     }
 
     // Now server is ready to listen and verification
     if (listen(args->sockfd, MAX_CONNECTION) == -1) {
-        printLog("Socket listening failed! (%s)\n", strerror(errno));
+        printErr("Socket listening failed! (%s)\n", strerror(errno));
         args->returnValue = 1;
         goto serverExiting;
     }
@@ -196,7 +196,7 @@ static void *serverMain(void *server)
     // Get server socket address structure
     if (getsockname(args->sockfd, (struct sockaddr *)&servaddr, &socklen)
             == -1) {
-        printLog("Could not get socket structure! (%s)\n", strerror(errno));
+        printErr("Could not get socket structure! (%s)\n", strerror(errno));
         args->returnValue = 1;
         goto serverExiting;
     }
@@ -212,7 +212,7 @@ static void *serverMain(void *server)
         if (connfd < 0) {
             // If error is not due to lack of clients connecting, this is error
             if (errno != EWOULDBLOCK && errno != EAGAIN) {
-                printLog("Server acccept failed! (%s)\n", strerror(errno));
+                printErr("Server acccept failed! (%s)\n", strerror(errno));
                 goto serverExiting;
             }
             sleep(1);
@@ -237,7 +237,7 @@ static void *serverMain(void *server)
                            serverCommunicationInstance,
                            (void*)&serverSlots[serverSlotIndex]);
             if(threadStatus != 0) {
-                printLog("Error from pthread: %d (%s)\n",
+                printErr("Error from pthread: %d (%s)\n",
                          threadStatus, strerror(errno));
                 args->returnValue = 1;
                 goto serverExiting;