diff --git a/level_zero/tools/source/sysman/linux/fs_access.cpp b/level_zero/tools/source/sysman/linux/fs_access.cpp
index 51fab819dd..624d72a379 100644
--- a/level_zero/tools/source/sysman/linux/fs_access.cpp
+++ b/level_zero/tools/source/sysman/linux/fs_access.cpp
@@ -22,7 +22,7 @@ static ze_result_t getResult(int err) {
     if ((EPERM == err) || (EACCES == err)) {
         return ZE_RESULT_ERROR_INSUFFICIENT_PERMISSIONS;
     } else if (ENOENT == err) {
-        return ZE_RESULT_ERROR_UNKNOWN;
+        return ZE_RESULT_ERROR_NOT_AVAILABLE;
     } else {
         return ZE_RESULT_ERROR_UNKNOWN;
     }
@@ -172,7 +172,7 @@ ze_result_t FsAccess::listDirectory(const std::string path, std::vector<std::str
     list.clear();
     ::DIR *procDir = ::opendir(path.c_str());
     if (!procDir) {
-        return ZE_RESULT_ERROR_UNKNOWN;
+        return getResult(errno);
     }
     struct ::dirent *ent;
     while (NULL != (ent = ::readdir(procDir))) {
@@ -184,6 +184,11 @@ ze_result_t FsAccess::listDirectory(const std::string path, std::vector<std::str
         list.push_back(std::string(ent->d_name));
     }
     ::closedir(procDir);
+    // Check if in above while loop, readdir encountered any error.
+    if (errno != 0) {
+        list.clear();
+        return getResult(errno);
+    }
     return ZE_RESULT_SUCCESS;
 }
 
diff --git a/level_zero/tools/source/sysman/sysman_device/linux/os_sysman_device_imp.cpp b/level_zero/tools/source/sysman/sysman_device/linux/os_sysman_device_imp.cpp
index a59c7662dc..1f537d571f 100644
--- a/level_zero/tools/source/sysman/sysman_device/linux/os_sysman_device_imp.cpp
+++ b/level_zero/tools/source/sysman/sysman_device/linux/os_sysman_device_imp.cpp
@@ -244,7 +244,11 @@ ze_result_t LinuxSysmanDeviceImp::scanProcessesState(std::vector<zet_process_sta
         uint64_t pid;
         result = pSysfsAccess->read(realClientPidPath, pid);
         if (ZE_RESULT_SUCCESS != result) {
-            return result;
+            if (ZE_RESULT_ERROR_NOT_AVAILABLE == result) {
+                continue;
+            } else {
+                return result;
+            }
         }
 
         // Traverse the clients/<clientId>/busy directory to get accelerator engines used by process
@@ -252,7 +256,11 @@ ze_result_t LinuxSysmanDeviceImp::scanProcessesState(std::vector<zet_process_sta
         std::string busyDirForEngines = clientsDir + "/" + clientId + "/" + "busy";
         result = pSysfsAccess->scanDirEntries(busyDirForEngines, engineNums);
         if (ZE_RESULT_SUCCESS != result) {
-            return result;
+            if (ZE_RESULT_ERROR_NOT_AVAILABLE == result) {
+                continue;
+            } else {
+                return result;
+            }
         }
         int64_t engineType = 0;
         // Scan all engine files present in /sys/class/drm/card0/clients/<ClientId>/busy and check
@@ -262,7 +270,11 @@ ze_result_t LinuxSysmanDeviceImp::scanProcessesState(std::vector<zet_process_sta
             std::string engine = busyDirForEngines + "/" + engineNum;
             result = pSysfsAccess->read(engine, timeSpent);
             if (ZE_RESULT_SUCCESS != result) {
-                return result;
+                if (ZE_RESULT_ERROR_NOT_AVAILABLE == result) {
+                    continue;
+                } else {
+                    return result;
+                }
             }
             if (timeSpent > 0) {
                 int i915EnginNumber = stoi(engineNum);
diff --git a/level_zero/tools/test/unit_tests/sources/sysman/sysman_device/linux/mock_sysfs_sysman_device.h b/level_zero/tools/test/unit_tests/sources/sysman/sysman_device/linux/mock_sysfs_sysman_device.h
index faa550b1f2..95da80aae1 100644
--- a/level_zero/tools/test/unit_tests/sources/sysman/sysman_device/linux/mock_sysfs_sysman_device.h
+++ b/level_zero/tools/test/unit_tests/sources/sysman/sysman_device/linux/mock_sysfs_sysman_device.h
@@ -12,11 +12,6 @@
 #include "sysman/linux/fs_access.h"
 #include "sysman/sysman.h"
 
-#if defined(__clang__)
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Winconsistent-missing-override"
-#endif
-
 using ::testing::_;
 
 namespace L0 {
@@ -50,12 +45,12 @@ struct Mock<SysmanDeviceSysfsAccess> : public SysfsAccess {
     ze_result_t getValString(const std::string file, std::string &val) {
         if (file.compare(subsystemVendorFile) == 0) {
             val = "0x8086";
-        }
-        if (file.compare(deviceFile) == 0) {
+        } else if (file.compare(deviceFile) == 0) {
             val = "0x3ea5";
-        }
-        if (file.compare(vendorFile) == 0) {
+        } else if (file.compare(vendorFile) == 0) {
             val = "0x8086";
+        } else {
+            return ZE_RESULT_ERROR_NOT_AVAILABLE;
         }
         return ZE_RESULT_SUCCESS;
     }
@@ -63,12 +58,18 @@ struct Mock<SysmanDeviceSysfsAccess> : public SysfsAccess {
     ze_result_t getValUnsignedLong(const std::string file, uint64_t &val) {
         if ((file.compare("clients/4/pid") == 0) || (file.compare("clients/5/pid") == 0)) {
             val = pid1;
-        }
-        if (file.compare("clients/6/pid") == 0) {
+        } else if (file.compare("clients/6/pid") == 0) {
             val = pid2;
-        }
-        if ((file.compare("clients/4/busy/0") == 0) || (file.compare("clients/4/busy/3") == 0) || (file.compare("clients/5/busy/1") == 0) || (file.compare("clients/6/busy/0") == 0)) {
+        } else if ((file.compare("clients/4/busy/0") == 0) || (file.compare("clients/4/busy/3") == 0) ||
+                   (file.compare("clients/5/busy/1") == 0) || (file.compare("clients/6/busy/0") == 0)) {
             val = engineTimeSpent;
+        } else if ((file.compare("clients/4/busy/1") == 0) || (file.compare("clients/4/busy/2") == 0) ||
+                   (file.compare("clients/5/busy/0") == 0) || (file.compare("clients/5/busy/2") == 0) ||
+                   (file.compare("clients/5/busy/3") == 0) || (file.compare("clients/6/busy/1") == 0) ||
+                   (file.compare("clients/6/busy/2") == 0) || (file.compare("clients/6/busy/3") == 0)) {
+            val = 0;
+        } else {
+            return ZE_RESULT_ERROR_NOT_AVAILABLE;
         }
         return ZE_RESULT_SUCCESS;
     }
@@ -78,12 +79,14 @@ struct Mock<SysmanDeviceSysfsAccess> : public SysfsAccess {
             list.push_back(clientId1);
             list.push_back(clientId2);
             list.push_back(clientId3);
-        }
-        if ((path.compare("clients/4/busy") == 0) || (path.compare("clients/5/busy") == 0) || (path.compare("clients/6/busy") == 0)) {
+        } else if ((path.compare("clients/4/busy") == 0) || (path.compare("clients/5/busy") == 0) ||
+                   (path.compare("clients/6/busy") == 0)) {
             list.push_back(engine0);
             list.push_back(engine1);
             list.push_back(engine2);
             list.push_back(engine3);
+        } else {
+            return ZE_RESULT_ERROR_NOT_AVAILABLE;
         }
         return ZE_RESULT_SUCCESS;
     }
@@ -91,9 +94,9 @@ struct Mock<SysmanDeviceSysfsAccess> : public SysfsAccess {
     Mock() = default;
     ~Mock() override = default;
 
-    MOCK_METHOD2(read, ze_result_t(const std::string file, std::string &val));
-    MOCK_METHOD2(read, ze_result_t(const std::string file, uint64_t &val));
-    MOCK_METHOD2(scanDirEntries, ze_result_t(const std::string path, std::vector<std::string> &list));
+    MOCK_METHOD(ze_result_t, read, (const std::string file, std::string &val), (override));
+    MOCK_METHOD(ze_result_t, read, (const std::string file, uint64_t &val), (override));
+    MOCK_METHOD(ze_result_t, scanDirEntries, (const std::string path, std::vector<std::string> &list), (override));
 };
 
 class PublicLinuxSysmanDeviceImp : public L0::LinuxSysmanDeviceImp {
@@ -103,8 +106,4 @@ class PublicLinuxSysmanDeviceImp : public L0::LinuxSysmanDeviceImp {
 };
 
 } // namespace ult
-} // namespace L0
-
-#if defined(__clang__)
-#pragma clang diagnostic pop
-#endif
\ No newline at end of file
+} // namespace L0
\ No newline at end of file
diff --git a/level_zero/tools/test/unit_tests/sources/sysman/sysman_device/linux/test_sysman_device.cpp b/level_zero/tools/test/unit_tests/sources/sysman/sysman_device/linux/test_sysman_device.cpp
index 6421045d05..fe086b996b 100644
--- a/level_zero/tools/test/unit_tests/sources/sysman/sysman_device/linux/test_sysman_device.cpp
+++ b/level_zero/tools/test/unit_tests/sources/sysman/sysman_device/linux/test_sysman_device.cpp
@@ -109,5 +109,10 @@ TEST_F(SysmanSysmanDeviceFixture, GivenValidSysmanHandleWhileRetrievingInformati
     EXPECT_EQ(processes[1].memSize, memSize2);
 }
 
+TEST_F(SysmanSysmanDeviceFixture, GivenValidSysmanHandleWhileReadingNonExistingFileThenErrorIsReturned) {
+    std::vector<std::string> engineEntries;
+    EXPECT_EQ(ZE_RESULT_ERROR_NOT_AVAILABLE, pSysfsAccess->scanDirEntries("clients/7/busy", engineEntries));
+}
+
 } // namespace ult
 } // namespace L0
\ No newline at end of file